Year of Publication


Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation


Arts and Sciences


Political Science

First Advisor

Dr. Mark Peffley


The 2000 US Presidential Election brought the confusing array of electoral rules to the minds of many in the mass media and politics. One reform advocated to improve the integrity of elections was to require voters to present identification at the polls prior to receiving a ballot. This particular reform generated much controversy, as critics worried that millions of citizens would be denied a ballot because they lacked government-issued photo ID, a form of ID advocated by many Republican officials. The controversy extended to the courts, with photo ID requirements upheld by a 6-3 US Supreme Court decision in 2008 in part due to the lack of evidence that ID laws prevented any citizens from voting. Consequently, over 30 states now require some form of ID of all voters in elections prior to receiving a ballot. Surprisingly, extant research has failed to uncover evidence of a consistent impact on voter participation. My research shows that the best way to understand whether and how voter ID laws impact turnout in national elections is to begin with a theory of how these laws are shaped by the strategic environment faced by the state political parties whose job is to win elections.

Using a variety of data sources, I examine how ID laws impact political participation in the US. This includes examining both what factors led some states to adopt these laws as well as their impact on voter participation and mobilization. I find that laws appear to be adopted primarily for strategic reasons rather than to combat voter fraud. States with growing minority populations and large gaps between midterm and presidential election turnout are more likely to enact photo ID laws than other states. Showing that partisan concerns impact adoption. However, using aggregate turnout from both states and counties in past federal elections I do not find any consistent negative impact. Surprisingly, photo ID laws appear to increase turnout in states with large African American populations, with a significant negative impact only in areas with few minority voters. I attribute this to a change in campaign strategy where Democratic groups are using laws to mobilize minority voters. Using survey data from 2010 and 2012 I show that African Americans are more likely to be contacted in states with photo ID laws, which helps explain the surprising impact of these laws on voter turnout. While ID laws may have been enacted to achieve a partisan advantage for Republicans, these reforms do not take place in a vacuum where they are immune to any response. Critics and opponents of voter ID requirements may be successfully using these laws to mobilize the very groups they are thought to suppress.

Digital Object Identifier (DOI)