Skip Navigation
Research Report

Developing Empirical Evidence for Campaign Finance Cases

Published: October 20, 2016

This report reviews the current state of campaign finance law, explains how the Supreme Court has considered evidence in campaign finance cases, and identifies the key empirical questions in campaign finance law that have been or need to be answered.

View on Scribd


In recent years, American election spending has soared but has come from fewer donors giving more money. Candidates now view the support of unlimited, sometimes anonymous, outside entities such as super PACs as practically essential to compete. Against this backdrop, Americans have consistently expressed the concern that wealth unfairly influences policy outcomes.

Yet, as powerful as these developments may seem, it is important to remember that their legal justification emerged for the most part from just a handful of recent 5-to-4 decisions by the U.S. Supreme Court beginning in 2007. That five-justice majority has since lost one member. Whatever the political context of filling the vacancy, to assume change will not come would be to miss a significant opportunity to shape the role of money in American elections.

This opportunity does not depend on adopting a particular advocacy stance, but merely requires a commitment to produce objective and reliable empirical research relevant to the major questions of campaign finance law. The opportunity exists because, simply put, the five-justice majority in its sweeping decisions to eradicate certain contribution limits, corporate spending bans, and public financing features, almost never considered or cited supporting evidence. Though the Court has expressed particular views about the ways politics and campaign finance regulation work, a close read of the justices’ opinions reveals strikingly little consideration of the actual effects of money or regulation on the political process. This shortcoming may explain the disconnect between the Court’s and the general public’s understandings of money in politics. While a change in membership will not guarantee a new campaign finance jurisprudence, a newly composed Court may be willing to reconsider recent precedents when presented with sound data addressing the unsupported assumptions that undergirded those decisions.

This paper aims to identify the key factual assumptions and conclusions that serve to justify the most important campaign finance decisions, catalog relevant existing research, and suggest further studies to test such assumptions and conclusions. Such studies could aid not only litigants and courts as they consider new campaign finance cases, but also policy makers, as they seek to understand problems, craft the best solutions, and build records to defend those solutions against virtually inevitable constitutional challenges.

Several notable efforts to advance empirical research about money in politics have already emerged. In 2013, the Campaign Finance Institute and the Bipartisan Policy Center published the expansive An Agenda for Future Research on Money in Politics in the United States, calling for detailed study of public financing, campaign spending disclosure, and independent spending after Citizens United, among other things. One of the leaders of that charge, Michael Malbin, has also provided deep analysis of the effects of small donor public financing systems. Lynda Powell has shown, through a massive survey-based study, when and how campaign contributions affect state legislators. In 2014, Renata Strause and Daniel Tokaji published an important paper urging researchers to gather legislator testimony, social science research, and press reports to show the conflicts of interest that campaign contributions and expenditures can create.10 But a systematic approach to aligning objective research efforts with the several critical legal questions of money in politics will increase both the social value of such research and the lasting efficacy of legal reform.

This report proceeds in three parts. Part I reviews the current state of campaign finance law, discussing the most important Supreme Court holdings and how they limit options for reform. Part II explains how the Court has considered evidence in deciding campaign finance cases, offering observations about when evidence has been most important and how it can change outcomes. Finally, Part III identifies the key empirical questions in campaign finance law, noting existing relevant research and suggesting additional research that would aid courts and policy makers.