The power of coalitions: lobbying success in US sanctions policy toward Iran from 2007 to 2016

This paper focuses on the role of interest groups in US sanctions policy toward Iran from 2007 to 2016. The aim of this work is to explain what changed in regard to the role of interest groups in the most significant shift in US-Iranian relations under President Barack Obama before and after the vote on the Joint Comprehensive Plan of Action, which was intended to halt Iran’s non-peaceful nuclear program in return for an easing of sanctions by the US Congress. This study contributes to our knowledge about how structural variables, issue salience, and actor strategies work together to produce outcomes. In addition, it provides a better understanding of interest group influence by identifying conditions under which interest groups can be successful in changing the policy status quo. This research proposes that the once firm stands of the Democrat legislators on supporting Iran sanctions changed due to support of President Obama’s strategy of engagement by Pro-Diplomacy groups and the international community, which he used as legislative subsidy. In addition, favorable policy windows opened up opportunities that pushed for diplomacy instead of confrontation.


Introduction
In the US political process, interest groups play an important role in shaping legislation. They provide votes and campaign contributions for political candidates but also offer important organizational support, supply information insight, and mobilize voluntary campaign staff. The increase in official lobbying spending from $1.45 billion in 1998 to $3.5 billion in 2020 shows the importance of lobbying in the United States (Duffin 2020). To analyze interest group involvement is, therefore, essential to a better understanding of the political processes in a democratic system. The aim of this article is to explain what role interest groups played during an important episode of policy change, namely, before and after the vote in the US Congress on the Joint Comprehensive Plan of Action (JCPOA), which was intended to halt Iran's non-peaceful nuclear program in return for an easing of sanctions and, which represented the most significant shift in US-Iranian relations under President Barack Obama. On July 14, 2015, the JCPOA was reached between Iran and the P5 + 1 (the permanent members of the United Nations Security Council plus Germany) and incorporated into law by the United Nations Security Council Resolution 2231. In order to avoid having to seek congressional approval that he was unlikely to get, President Barack Obama defined the agreement as a political commitment among the nations involved, instead of as a treaty that would require congressional ratification. However, due to congressional pressure, Obama signed a compromise bill in April, the Iran Nuclear Agreement Review Act of 2015, which enabled legislative review of any deal with Iran before the lifting of US sanctions (Weisman and Baker 2015). The House of Representatives had in the past shown bipartisan support for sanctioning Iran as a means of stopping its nuclear program. Under those conditions, a two-thirds majority in favor of a confrontational strategy would have easily been accomplished to override a potential presidential veto in case of a rejection of the deal by Congress. What happened instead, however, was that the vote on the nuclear deal on 10 September 2015 turned out to be the beginning of a divide on party lines in regard to US foreign policy with Iran. The deal survived because of a change in the Democrats' support: A Democratic filibuster led to a failed vote on the resolution of disapproval of the deal in the Senate and an unprecedented 94% of Democratic members voted against Republicans seeking to block the deal in the House of Representatives. The significance of the break from the traditional support of Iran sanctions by the legislators in the House of Representatives is evident given that between the 110th and 113th Congress, legislators were almost united in voting in favor of sanctions. Only in the 114th Congress did approval of sanctions drop to 58%, of these, 99% were Republicans, and 6% were Democrats (see Fig. 1).
The goal of this case study is to elucidate the role that interest groups played in bringing about changed support for sanctions in Congress. Interest groups were very active in this policy domain, and yet the conventional literature argues that the US political system favors groups that aim to delay or obstruct new positions or policies rather than those groups which promote or introduce policy change (Grant 1979: 162-163). Given this expectation, it is not surprising that 81% of those interest groups promoting the status quo were at least partially successful in reaching their goals (Mahoney 2008: 52). A change in the status quo is rare, but if it occurs it is a significant change that warrants explanation (Baumgartner et al. 2009: 239-241;Mahoney 2008: 54). The relevance of this study is that it seeks to analyze the reasons for the sudden shift in Congress with respect to US foreign policy on Iran sanctions and, specifically, to assess the changing conditions that facilitated the success of interest groups lobbying for a shift in policy. To this end, it seeks to trace the causal effect of a variety of factors on the lobbying success of interest groups. The significance of this case along with the fact that such policy shifts are relatively rare make this case study particularly suitable for studying the conditions under which interests groups can move from lack of success to successful influence. The single case cannot be representative and may itself not be generalizable, but it is highly useful as a pathway case that allows us to trace out causal factors often identified in the literature (on pathway cases, see Gerring 2006). This paper presents a systematic examination of a variety of factors linked to lobbying success with Iran during the period of rising US sanctions in the 110th Congress (2007Congress ( -2008 through to the path toward diplomacy adopted in the 114th Congress (2015)(2016). The research focuses in particular on the House of Representatives as this in an institution most vulnerable to interest group pressure due to the limited resources of its members and the rising costs of election campaigns aggravated by the short two-year term.

Theoretical argument
This article considers legislation outcome to be the main indicator for the lobbying success of interest groups. The most relevant factors supporting lobbying success are divided into two categories for improved comparability: characteristics of interest groups and domestic and international political context. The factors will be discussed and embedded in the literature in the following paragraphs in order to enable a subsequent comparison to other scholars' work on the conditions for interest group influence. The first set focuses on inside factors, such as financial contributions, coalition-building, and organizational strength. The factors of the second category focus on the outside, which includes the impact from media attention, presidential support, and policy windows created by the international context.
The groundwork for interest group involvement originates in the pluralist system of the United States. The establishment of this pluralistic state can be traced back to James Madison's early concept of checks and balances where politically engaged groups would equally compete for influence in the decision-making process. To avoid majority rule, power was to be divided with checks and balances (Madison 1787). 1 The legislature, executive, and judiciary, but also independent regulatory commissions, take up important roles in the separation of powers, providing different access points to interest groups.
There are three main aspects of the political system of the United States that explain the need of legislators to make alliances with interest groups: the decentralized policy making structure, the limited importance of political parties, and the electoral system (Berry 1989;Paul and Paul 2009, 7-8). In regard to the latter, the system of public office nominations via primaries instead of the party leadership increases the dependence of political candidates on their constituents, and therefore, also on interest groups (Smith 2000: 93). The dependency further rises because political parties have only limited ability to raise money, leaving candidates to fend for themselves (Cigler 1983: 20;Grant 1979: 151). With re-elections every 2 years for all 435 members of the House and a third of the members of the Senate, the members of Congress heavily depend on pleasing their electorate and on raising financial contributions and are, therefore, very vulnerable to interest group pressure (Watanabe 1984: 21-22;Tierney 1994: 103-106). Another aspect that intensifies the legislators' dependence on the mobilization of votes by interest group, i.e., alliances with interest groups, is the general low voter turnout rate with an average of 55.4% (for 2000-2016, see United States Election Project 2017). Electoral polarization has led to another rise in coalitions between parties and interest groups over the last decades (Berry and Wilcox 2018: xiiv). The stronger reliance on only one party for support has limited the ability of interest groups to work with both sides of the aisle, which can negatively impact lobbying success.
In regard to domestic policy, interest group influence has been heavily studied, the role of interest groups in influencing foreign policy has, however, been relatively neglected. In order to explain the origins of US foreign policy, the liberal school of international relations has most prominently analyzed domestic structures and internal groups, as "[…] the configuration of state preferences [that] matters most in world politics-not, as realists argue, the configuration of capabilities and not, as institutionalists […] maintain, the configuration of information and institutions" (Moravcsik 1997: 513). The constant bargaining of interests that underpins the interdependence of domestic and foreign policy (Risse-Kappen 1991: 480-488;Beyers et al. 2008Beyers et al. : 1104) is a "two-level game," in which legislators simultaneously act within the framework of domestic restraints and external conditions. To "win" the domestic acceptance for an issue, the legislator works together with societal actors and builds coalitions with them. The achieved outcome, i.e., "win-set," must be agreed on by the domestic interest groups in order to gain the needed backing for the policy decision. On the international level, the win-sets of the involved nation states then need to overlap for a final treaty to be reached (Paul and Paul 2009: 46;Putnam 1988: 434). For foreign policy issues, interest groups concentrate on the Defense and State Departments and relevant congressional members.
The dependence of interest groups as allies is often based on the limited resources of a legislator and a reliance on external expertise as well as financial and organizational support. This dependence is best described as legislative subsidy (Hall and Deardorff 2006: 69;Hall and Miler 2008: 990-991). A legislative subsidy can have many different aspects: it can be a direct alliance with a group or it can signify an external event or measure pushing a certain policy outcome. Here, scholars commonly differentiate between two strategies interest groups make use of: inside lobbying, where legislators are directly approached, and outside lobbying, where the pressure on a legislator is created via the media, the public, or external events (Beyers 2004;Dür and Mateo 2016, 70). Inside lobbying can mean providing expertise and advise to congressional staff and public office holders in order to push a policy or public endorsements. This is quite common because staffers tend to depend on information provided by interest groups due to a lack of expertise, in particular in regard to foreign policy issues (Bouwen 2002;Dür and De Bièvre 2007: 3;Dür and Mateo 2012;Grossman and Helpman 2001;Jones 2011: 2;Mahoney 2007Mahoney : 35-36/2008Olson 1965, 198). Outside lobbying can include unplanned events but also public campaigns, such as grassroots mobilization of members and of the public, political debates, public meetings, speeches, protests, publishing advertisements or articles aimed for public education (Mahoney 2008: 129). The use of different lobbying techniques has been demonstrated to be more successful than focusing on one lobbying technique (Baumgartner and Leech 1998;Jones 2011: 5;Skidmore 1993: 230;coalitions: Hojnacki 1997, Hula 1999outside lobbying: Kollman 1998).
Overall, important advances have been made in recent years in furthering our understanding of the impact of organized interests on policy outcomes in the political systems of the United States (Baumgartner et al. 2009), the EU (Klüver 2013) and the United Kingdom (Bernhagen and Trani 2012), as well as comparatively for different states (Mahoney 2007). Yet, despite their methodological and data advances, these studies share many of the problems highlighted by Lowery (2013), including the problem of identifying lobbying success. A major problem researchers face is the difficulty of attributing desired policy outcomes, the question of influence, to the success of the interest groups' strategies. This study investigates the factors of lobbying success from interest groups by serving as a legislative subsidy on various different levels, from the benefits of the resources of interest groups and of working in a coalition, to the influence of media attention, presidential support, and policy windows. To explain why the factors were selected for the previously mentioned categories interest group characteristics as well as domestic and international context, their importance based on existing literature is described in the following. In the empirical part, their significance for this case study will then be analyzed.

Factors relevant for the characteristics of interest groups
(1) Financial contributions To run in US elections is expensive because of the enduring election process, little party backing for support, the need to employ experts, and costly media campaigns and polls in order to test strategies. As only presidential candidates receive party funds, which finances part of the expenses of their campaigns, House and Senate candidates compete for funds and depend on interest groups for support: they mobilize their members to vote, provide volunteers and other resources to the campaign. As access means everything for influencing policy-makers, funding campaigns is an important tool for interest groups (Grant 1979: 151, 188-171;Keck 1998: 28-29;Niemi and Dyck 2013: 121;Smith 2000: 93). In the election cycles of 2012-2016, the average winner spent about $1.6 million on her or his campaign, whereas in 2020 the amount already resulted to $2.4 million (Malbin and Glavin 2020; The Campaign Finance Institute 2020; OpenSecrets.org 2019). 2 Despite the obvious need for financial contributions, donations cannot clearly be linked to the ability to shape policy outcomes (Baumgartner and Mahoney 2008;Burstein and Linton 2002;Binderkrantz 2005;Beyers and Kerremans 2007). However, the data does allow the conclusion that money provides access (Magleby and Nelson 1990;Langbein study 1986Langbein study : 1052.
(2) Coalition-building Working together in a coalition is one of the most common tactics that groups use as it is an effective way of sharing resources to organize initiatives and shape policies. Unequal competition with adversaries is the obvious reason why coalitions are formed and this is, in particular, the case when interest groups want to challenge the status quo and change existing policies (Baumgartner et al. 2009: 202;Mahoney and Baumgartner 2014: 213;Berry 1989;DeGregorio and Rossotti 1995;Hojnacki 1997;Hojnacki et al. 2012;Hula 1999: 241;Schlozman and Tierney 1986: 278). In a coalition, interest groups are able to intensify the importance of their message, which is most convenient for highly salient issues. In this case, it will be evaluated if the selected interest groups chose to work in a coalition to reach a shared policy goal or not. (3) Organizational strength Strong interest groups are more effective in reaching their goals. The factor "strength" comprises a variety of resources such as lobbying expenditures, revenues, staff (Ambrosio 2002: 10-13, Mahoney 2008, as well as salaries and the founding year.

Factors relevant for the domestic and international political context
While the first category, characteristics of interest groups dealt with factors based on interest groups themselves, the domestic and international political context contains external factors that might contribute to lobbying success.
(1) Media attention "The greatest obstacle for lobbies needing media attention to help them persuade policy-makers, is to get the media to pay attention in the first place.
[…] To get any kind of coverage is a major victory for many lobbyists around town." (Baumgartner et al. 2009: 183) Several studies agree that high salience is a necessity for influence-taking (Browne 1990;Mann 1990: 14;Skidmore 1993: 231;Smith 2000: 120). However, salience can also be a sign of too much controversy, which might lead legislators to turn away from an issue (Mahoney and Baumgartner 2014: 204). A single interest group has a lower chance of lobbying success in regard to a highly salient issue than when acting in a coalition because with high salience the scope of an issue usually increases.
With large-scope issues, the attraction to form ad hoc issue coalitions rises as this enables the interest groups to show the united strength of a movement and to have an important political voice (Mahoney 2008: 40-41).
(3) Policy windows The sudden occurrence of opportunities for lobbying success may stem from a changed involvement of the international community (Lindsay 1994: 202) or other focusing events (Kingdon 1984: 165ff;Mahoney 2008: 41). A focusing event alters the attention of policy-makers and the public in regard to an issue as its importance rises or declines as an effect. This event can create momentum for policy change that interest groups, which seek a break from the status quo, can benefit from (Mahoney 2008: 41).
Given the complexity of the environment in which all these factors play a role, it becomes clear that not one factor can lead to the lobbying success of an interest group, but rather, a combination of these factors.

Research design
The central question of this study is how lobbying affects policy success, as this comes closest to understanding why interest groups fail or succeed and under which circumstances (Baumgartner and Mahoney 2008). Lobbying success is here defined as reaching a policy outcome that is closer to the interest group's goal than would have been likely without any interest group engagement (Berry 1989: 83). To analyze the lobbying success of interest groups, as in reaching a policy goal, the dependent variable policy outcome was set in relation to the factors linked to lobbying success. Concentrating on the issue context enabled to answer the question not whether interest groups are influential but "when, why, and to what extent they are powerful on what types of issues" (Baumgartner and Leech 1998: 134). The specific political context factors gave insight into the conditions of lobbying success and, thereby, advance our understanding of groups, politics, and policy making in general. The factors were divided into the categories: characteristics of interest groups and the domestic and international political context. The dependent variable was operationalized by the variation in voting behavior in recorded roll calls. This variable operating on the district level was put in relation with those factors, which also provided data on the district level, i.e., financial contributions. For the second part of the analysis, the dependent variable was operationalized by the variation in the amount of introduced, passed, and dead resolutions in the House in order to show the general trend in the policy outcome in favor or against sanctions toward Iran per Congress Period. This operationalization was used when the factors for lobbying success also showed trends, such as coalition-building, organizational strength, media attention, and policy windows.
The resolutions for this study were chosen based on content related to sanctions legislation or diplomatic engagement with Iran introduced in the 110 th -114th Congress. The total number of resolutions includes 69 resolutions (16 roll calls and 53 resolutions without votes, dead resolutions). Before the 114th Congress period, about 95% of all votes were "Yes-Votes," legislators voting in favor of sanctions, and 2-3% "No-Votes" against sanctions as well as 2-3% "NV-Votes," not voting legislators. 3 This research used a variety of quantitative methods to analyze empirical data, process-tracing based on qualitative interviews, and media information. 21 semistructured interviews with interest group representatives and congressional staff from Republican and Democrat offices involved in the US policy making process with Iran prior to the JCPOA enabled insight into the issue context and clarified important points on the most influential actors involved, their tactics as well as external influences. 4 For this study interest groups were selected with a substantial financial backing and an important political voice, i.e., groups that interacted with policy-makers on issues related to Iran. Groups were selected using quantitative thresholds: Interest groups had to submit at least four lobby reports during the time frame of 2007-2014 containing the keyword "Iran." In addition, the interest groups' lobby expenditures had to exceed a certain financial minimum, which was set at $20,000, for at least two election cycles during the 110th-113th Congress periods, i.e., the years 2007-2014. For generalizability and improved comparability, the groups were divided into two clusters, those supporting sanctions and those supporting a diplomatic approach. The division into a Pro-Sanctions side and a Pro-Diplomacy side was based on the overall goal of the interest groups. The interest groups below are those that fulfilled these preconditions and provided the necessary data for the selected factors. There is one group that switched sides, J Street officially supported a diplomatic approach only starting with the 114th Congress period. This is why the group was initially in the category "Pro-Sanctions" and later in "Pro-Diplomacy." The interviews conducted for this paper confirmed the relevance of the selected interest groups. 5

Empirical analysis
The empirical findings for the previously mentioned factors are presented in the following sections. The findings are put in context with the other factors in the conclusion.
(1) Financial Contributions When comparing the mean donations per legislator 6 from the respective groups the contributions from two groups stood out: AIPAC plus its affiliates, 7 and J Street. Other Pro-Sanctions groups and Pro-Diplomacy groups had relatively insignificant donations and were therefore disregarded. Even though J Street split from the Pro-Sanctions cluster during the 114th Congress period, it is likely that the group already started supporting the Pro-Diplomacy cause during the 113th Congress period. J Street's growing strength can be seen prior to the 114th Congress period through its financial contributions and the increased funding from the Ploughshares Fund (see coalition-building). During the 113th Congress period J Street's financial contributions rose to the level of the Pro-Sanctions groups, it also tripled the number of legislators donated to (see Figs. 2, 3). There were still considerably more legislators who received Pro-Israel donations, but the rising lobbying expenditures of J Street and its coalition partners established a more balanced equilibrium in regard to higher access to legislators.
(2) Organizational Strength The overall strength of the Pro-Sanctions side surpassed the strength of the Pro-Diplomacy side by far, which might have supported the favorable voting toward sanctions in previous Congress periods. Strength is here defined by the amount of lobby expenditures, revenues, salary levels, and staff (see Fig. 4 and Tables 1, 2, 3). The rising financial strength of the Pro-Diplomacy side as seen in the lobby expenditures during the 114th Congress period shows the increase in importance of these groups. 8 The declining bipartisanship of AIPAC and, thereby, the reliance on this previously most important interest group in US foreign policy in regard to Iran weakened despite its strength, as will be described in more detail in the conclusion. The Iranian lobby National Iranian American Council (NIAC) has been a key advocate against war with Iran since its founding in 2002 and has been working closely with J Street, the Center for Arms Control and Nonproliferation as well as USA * Engage and others. The Ploughshares Fund's annual contribution to the organization of $100,000 between 2012 and 2014, and twice as much in 2015, demonstrates the group's importance. It is mentioned due to the group's engagement but can only partly be included as it does not fulfill the conditions of being a registered lobby group or having affiliate lobby groups such as AIPAC. Apart from the coalitions by the selected interest groups for this study there were many coalitions by individuals on both sides who op-eds, or other initiatives. An expert from the Atlantic Council and a representative of NIAC stressed the importance of acting together in a coalition. 10 The contributions by the Ploughshares Fund supported the financial strength of several Pro-Diplomacy groups: The top recipient of contributions within the selected interest groups is J Street, which underlines the rising importance of this group (see Table 4). The annual contributions were $100,000 from 2012 to 2014, $150,000 in 2015 and $185,000 in 2016. To support the group's lobbying activities right before the crucial vote of the legislators on the JCPOA, J Street's PAC, the J Street Education Fund, received another $426,500 in 2015. 11 J Street's switch to the Pro-Diplomacy side in the 114th Congress period was essential for their lobbying success, as the group represented a Jewish perspective in favor of the Iran deal, which stood in contrast to that of AIPAC. This signified a guarantee for legislators to not be framed as anti-Semitic, which will be discussed further in the conclusion.
From the Pro-Sanctions side AIPAC was the strongest lobbying group but primarily acted on its own. In order to react to the strong Pro-Deal campaign by President Obama and the Pro-Diplomacy groups, AIPAC formed the non-profit organization Citizens for a Nuclear Free Iran in 2015 including former members of Congress with a budget of $20-40 million for television ads (Fenton 2015). This budget alone was about the same as the combined budget of eight of the biggest Pro-Diplomacy groups, which amounted to over $30 million (Clifton 2015;Ho 2015). 12 (4) Media Attention Depending on the issue it is essential to gain the attention of the media to influence legislators. The media attention in regard to sanctioning Iran did not change much between the 110 th -113th Congress periods. 13 But during the 114th Congress period, the media coverage was suddenly three times higher than in any other Congress period starting with the time of the vote on the JCPOA and its implementation as well as the following Iran sanctions resolutions (see Fig. 5). Three interest group representatives from the Pro-Diplomacy side mentioned that without the attention from the public through the media they would not have been as successful. 14 10 The interview with the NIAC representative was conducted on July 3, 2017, and the interview with the Iran expert of the Atlantic Council was conducted on July 7, 2017. 11 As the J Street Education Fund is a PAC, it is not considered in this research but the amount of received contributions from the Ploughshares Fund shows the fund's support for J Street, the interest group behind the PAC. 12 For more details, see Supplemental Information VI. 13 The number of media publications is derived from LexisNexis searches with the keywords "Iran" + "sanction." The selected time frame for each resolution ranged from the introduction date of the resolution to the date of the vote on the resolution; for dead resolutions the end point was set to seven days after the last registered action as found at Congress.gov. To limit the search findings, only the most important US newspapers were selected: The Washington Post, The New York Times, and the Wall Street Journal Abstracts. 14 The interviews with the representatives of the Arms Control Association and NIAC were conducted on September 1, 2015 and on July 3, 2017, respectively. See the Washington Post for the statement of J Street (Ho 2015).
(5) Presidential Support The support of the president for the goal of an interest group, or the lack thereof, can determine the lobbying success of the group. In the case of the nuclear deal with Iran, the Pro-Diplomacy side gained momentum as soon as President Barack Obama became more engaged in the negotiations with Iran. 15 He turned the former bipartisan Congress on that issue to a partisan one with the support and expertise of the Pro-Diplomacy groups.
When Obama took office, he made it very clear that he wanted to start a new chapter in US-Iranian relations in favor of diplomacy (The Atlantic 2013). This was part of his bigger strategy to focus on diplomacy and engagement as well as push      for America's return to multilateralism in international affairs-also in a means of sharing burdens with allies (Dueck 2015: 152;Gerges 2013: 301). As a first step, the United States started to fully participate in the P5 + 1 talks. However, the Obama administration intensified President Bush's sanctions regime: During the 112th Congress Period President Obama issued six Executive Orders sanctioning Iran, an exceptionally high amount of presidential sanctions. In addition, world powers united in the economic war against Iran with China and Russia supporting the US-EU-initiative of sanctioning Iran's oil and banking sector by means of six UNSC resolutions. This global consensus created maximum pressure by the international community, which was most effective in damaging Iran's economy.
With the reelection of President Obama and the election of President Hassan Rouhani in 2013, a team was established on both sides, which, for the first time since 1979, was seriously committed to settling the nuclear conflict between the two countries (Gerges 2013: 323). In order not to endanger the Iranian engagement, Obama asked Congress to hold off on new sanctions. The number of Iran resolutions introduced by House representatives accordingly dropped to the lowest number of passed and dead sanctions resolutions. On November 24, 2013, an interim Joint Plan of Action could be agreed upon by the P5 + 1 and Iran.
With the president's close alliance to Pro-Diplomacy groups, in particular Jewish groups like J Street and APN, Democratic legislators were convinced to oppose the much stronger AIPAC without fear of revenge. 16 Only a single Pro-Sanctions resolution was introduced at the end of the 113th Congress period. In the meantime, the administration issued seven installments of frozen Iranian assets in compliance with the interim deal. During the 114th Congress period, the White House asked Pro-Israel groups to tone down their rhetoric regarding Iran and new sanctions legislation as not to endanger the negotiations (Fabian 2015). After the final agreement with Iran and the P5 + 1 was reached in July 2015, Obama sent the JCPOA to Congress for approval. The debate on the JCPOA ended with a failed vote on a In the House, the majority approved the same resolution, i.e., the disapproval of the deal, but an unprecedented 94% of the Democratic members voted against it.
In the end, President Obama managed to succeed in enforcing his biggest foreign policy achievement and changing US strategy with Iran without Republican support. Obama did also not have a high approval rating and was in need for allies, which is why the White House actively met with interest group representatives to garner support for the Iran deal. It can therefore be assumed that the alliance with these groups was needed to help push the Democratic legislators to vote for a diplomatic solution with Iran. During the 111th Congress period a rise in Iranian nuclear activities occurred, that was matched by the highest number of sanctions resolutions introduced during the 110th-113th Congress periods. The advancement of Iran's nuclear program continued during the 112th Congress period and provoked a particularly strong increase in the number of international sanctions by the EU and UN as well as in presidential sanctions. These actions led to a low number of Pro-Sanctions resolutions in the House of Representatives. At the end of the 112th Congress period Israel's Prime Minister Benjamin Netanyahu's support of the competing Republican presidential candidate Mitt Romney started to alienate Democrats from the goals of AIPAC due to its close link to the Likud party (Sherwood 2012).
During the 113th Congress period, Iran was very active in trying to reach a diplomatic solution, and measures by the international community as well as by President Obama had the same objective. In November 2013, the P5 + 1 and Iran agreed on a Joint Plan of Action. One very influential event during this time was President Hassan Rouhani's election that played an important role in the success of Pro-Diplomacy initiatives, as he emphasized the need for improved relations with the West and, thereby, broke with the confrontative approach of his predecessor, Mahmoud Ahmadinejad (Dehghan 2013). The impact of the diplomatic endeavors was reflected in the low amount of congressional activities: In the House of Representatives one resolution was passed sanctioning Iran and four were introduced, the lowest amount within the selected time frame of 2007-2016.
Despite a rise in sanctions legislation introduced during the 114th Congress period threatening the nuclear deal, Pro-Diplomacy measures from the Iranian side and the international community managed to secure the agreement. One very influential event before the reaching of the agreement was the address by Israel's Prime Minister Netanyahu in front of a joint session of Congress urging to stop the nuclear deal in March 2015. This signified a break from diplomatic protocol, as there was no prior invitation or consultation with the White House. By openly confronting President Obama, Netanyahu infuriated the Democrats. One staffer of a Democratic representative remembered: "[…] A lot of members felt insulted. AIPAC decided to make a strong effort of letting the phones ring to attend [but they] misplayed it" 18 : 50 House members and 8 senators did not attend his speech in protest (Jaffe 2015). This action may have resulted in rising support for President Obama's objective in reaching the JCPOA, as "extremely partisan issues might draw a policy-maker to the fight to make sure their party's side of the story is heard." (Mahoney and Baumgartner 2014: 204).
The policy windows during the 113th-114th Congress periods opened up new opportunities for the Pro-Diplomacy groups in favor of a strategy change. These included events that occurred in Iran and measures taken by the international community in favor of a diplomatic solution as well as the polarizing actions of Israel's Prime Minister Benjamin Netanyahu.

Conclusion
In respect to the impact of interest groups on US-Iranian foreign policy making, for this study structural variables, issue salience, and actor strategies were analyzed. The findings underline that a shift in power relations, in which the success of interest groups supporting a diplomatic approach toward Iran relied to a high degree on a changed power equilibrium. Before the JCPOA, Pro-Sanctions groups used to only defend the status quo without having to fear a strong opposition from competing groups. AIPAC, for example, the most important interest group of the Pro-Sanctions side, used to work in the background and have strong relations to legislators for whom they provided information, drafted sanctions legislation, collected co-sponsors, and marshaled votes. 19 According to former AIPAC representative Douglas Bloomfield, it was common "for members of Congress and their staffs to turn to AIPAC first when they need[ed] information, before calling the Library of Congress, the Congressional Research Service, committee staff or administration experts.
[AIPAC was] often called upon to draft speeches, work on legislation, advise on tactics, perform research, collect co-sponsors and marshal votes." (Mearsheimer and Walt 2006) The strategy of the Pro-Sanctions side was to avoid too much attention and to rely on financial and organizational power.
However, a number of factors changed, which then led to the declining success of the interest groups pushing for sanctions policy, in particular of AIPAC. When Barack Obama became president in 2009, he pushed for a strategy of diplomatic measures toward Iran. Instead of following the policy of his predecessor President George W. Bush, he aimed to limit US military involvement abroad and propagated cooperation between nations instead of domination (Doran 2015). In the interviews conducted for this research, ten out of fifteen congressional staffers, and all six interest group representatives, overall 76%, named the president as the most important reason for the shift in US foreign policy toward Iran. This change in the administration's approach added credibility to the Pro-Diplomacy groups. 20 And, vice versa, these groups were an important tool for the administration: In the interviews conducted for this paper the congressional staffers emphasized the mutual benefit of the close cooperation between Pro-Diplomacy groups and the president in favor of the nuclear deal. A staffer and a representative of APN confirmed that the Obama administration relied on their expertise due to a lack of experts within the administration. 21 A representative of NIAC stated that there were "lots of briefings from Pro-Diplomacy groups, every 2 weeks or months." 22 Deputy National Security Advisor Ben Rhodes admitted, there were many briefings at the White House to strengthen the Pro-Diplomacy side and their arguments in 2013 to counter the strong anti-deal campaign that, in particular, AIPAC and the Likud party were driving (Rhodes 2018: 340). The Pro-Diplomacy groups served as a legislative subsidy as Obama relied on their support for convincing the Democrats to change their approach on Iran. An increasingly important factor due to Obama's unpopularity, which is reflected in the disapproval of his Presidency rising from 20% in the beginning of 2009 to 45-50% during 2010-2016 (Zeleny 2010;Gallup 2017). Without garnering enough support together with his allies, he might have likely failed. An essential aspect was Jewish partners like J Street, who switched to the Pro-Diplomacy side the moment Obama was reelected as President. J Street and APN provided an essential backing for the legislators supporting the deal because they ensured that the members would not be portrayed as anti-Semitic or anti-Israel. 23 Founder and executive director of J Street Jeremy Ben-Ami underlined: "We're trying to redefine what it means to be pro-Israel. You don't have to be noncritical. You don't have to adopt the party line." (Traub 2009) One staffer confirmed that "AIPAC is less powerful as alternative groups have appeared. J Street gets more attention now." 24 There were additional factors that turned the Pro-Diplomacy groups into serious competitors: rising financial support and additional resources, also based on their strong coalition. With rising lobbying expenditures, they also became stronger competitors for gaining access to legislators. But the heightened reliance on outside lobbying strategies, such a media campaigns, increased the need for more funding. Even though the Pro-Diplomacy side's budget rose significantly under the Obama administration, the Pro-Sanctions side's budget was still out of reach. The high media interest during the time of the vote on the Iran deal, however, evened out this disadvantage.
Turning to the external factors that supported the rising influence of the Pro-Diplomacy side, the actions by the international community were essential. This included the coordinated initiative to sanction Iran stopping the fast expansion of Iran's nuclear program, and the united front, which enabled the reaching of a diplomatic solution that followed. The commitment of the P5 + 1 turned the deal into a multilateral effort and heightened the pressure on US legislators to support the deal. Key policy windows further supported the Pro-Diplomacy side: Hassan Rouhani's election as Iran's President in 2013 improved the public image of Iran: Rouhani had campaigned for improved economic conditions and was eager to reach an agreement with the international community. Even though bilateral negotiations had already been taken up under his predecessor President Mahmoud Ahmadinejad, Rouhani signified a much more moderate face who was openly committed to a diplomatic solution. The public insult to President Obama by Israel's Prime Minister Benjamin Netanyahu also played an important role. The hostility between the two heads of state had been fueled by Netanyahu's endorsement of the Republican candidate Mitt Romney during the presidential campaign of 2012, which irritated Democratic members. When Netanyahu spoke in front of a joint session of Congress warning before the looming deal with Iran in March 2015, he seriously offended the Democrats. 25 As a consequence of Prime Minister Netanyahu's actions, AIPAC, his ally on US soil, could not rely on its former bipartisan influence on Congress, which weakened their campaign against the JCPOA. 26 AIPAC's diminishing influence signified the "most important shift [because it showed that] AIPAC is not that infallible group and gets what it wants," as stated by one staffer. 27 Another staffer added that "AIPAC [..] [had] been digging this hole for a decade, as they are being more right wing and more hostile to members who are not 100% with them." 28 In addition, the rising public attitude against war was another important factor that pushed legislators to support a diplomatic approach. After the Iraq war, the approval ratings by the public had dropped for proposed military interventions 29 : 76% of Americans said that if their representative would vote in favor of a military action against Syria, this would have negative consequences on their future voting behavior (The New York Times 2013). The rhetoric of the Pro-Diplomacy side describing war as the only alternative to the deal with Iran, added to the pressure on legislators to avoid a military intervention. This public anti-war sentiment was a useful tool for the Pro-Diplomacy side, which was confirmed by four staffers, an employee of RJC and the Foreign Policy Initiative as well as a journalist of the Jewish Telegraph Agency. 30 This article focused on the involvement of interest groups and the factors leading to lobbying success. The factor coalition-building for reaching a policy change turned out to be essential confirming the finding that "lobbyists, like wolves, work in packs" (Mahoney and Baumgartner 2014: 214). In this case, the forming of a coalition and joining of resources between President Obama, the international community, and interest groups appeared to be essential for a policy change. The previous lobbying success of the Pro-Sanctions groups was based on a vast amount of resources combined with bipartisan congressional influence, and a reliance from legislators on their expertise. On the other hand, the Pro-Diplomacy groups turned into serious adversaries due to the policy shift in the administration, the loss of bipartisanship from the Pro-Sanctions side, the rising polarization within Congress, the unity of the international community, and supporting policy windows. The polarization was increased by President Obama's push against the status quo and the question of loyalty for the Democrats to support their president. Prime Minister Netanyahu's agitation against President Obama, which was supported by AIPAC, added fuel to the partisan divide. What also strengthened the standing of the Pro-Diplomacy groups was the increase in donations they received, as well as the combined resources due to the establishment of their strong coalition. The high media visibility additionally supported them in promoting their positions. With Jewish groups backing the President goal of reaching the JCPOA, Obama gathered enough support to persuade his party that being for the deal did not mean to be against Jewish interests per se. This mixture of factors led the Democrats to vote for the Iran deal and enabled the until then unprecedented partisan divide on Iran.
This study is one of few factor-related approaches that includes different interest group types, such as ethnic lobbies, peace groups, and business lobbies. A set of relevant factors was derived from literature and tested in regard to lobbying success. The most important contribution of this study in regard to interest group research is the increased knowledge about how a variety of existing criteria such as structural variables, issue salience, and actor strategies work together to produce outcomes. Second, this work advances the understanding of interest group influence by identifying conditions and reevaluating criteria under which interest groups can be successful in changing the policy status quo. It further contributes to recent studies, which link lobbying success to policy outcome (Baumgartner et al. 2009;Dür and De Bièvre 2007;Klüver 2009;Mahoney 2008). As policy processes are shaped by a multitude of interacting forces and actors, it is almost impossible to predict with absolute certainty the likely consequences of a set of activities on policy, and extremely difficult to pin down the full effect of actions even after the event.
Since interest group research lacks an established methodological norm, a standardized method to investigate lobbying success based on a tested set of factors would be desirable in the future. The existing methodological differences in operationalizing lobbying success make comparisons between case studies very difficult, as the dependent variables vary from roll call votes, media attention, access, behavioral change in key actors, the framing of debates, commitments from states, and policy outcomes and many more. The challenge of a standardized method in measuring lobbying success lies in the lack of an obvious unit of measurement or simple way of ranking as well as insufficient data. Due to the lack of hard data, surveys are often used for empirical data but self-estimations can be biased, exaggerate or down play influence; plus, lobbyists don't want to share how they became successful, and policy-makers don't want to admit lobby influence. While small scope studies present extensive knowledge of all factors involving a policy decision, their data is specific to individual research projects, and the knowledge gained for relevant conditions therefore limited. With this study, a systematical test of factors for interest groups was conducted in order to establish a set for relevant factors to be used in studies to come. In order to draw general conclusions for these factors future studies would need to systematically combine explanatory variables for a larger number of policy issues and interest groups, across different levels of government, larger timeframes, and varying nation states.