Voting Rights Research: What Studies Show About Voter ID, Access, and Participation

Voting rights policy in the United States involves fundamental questions about who can vote and on what terms, with ongoing legal and political battles over voter identification requirements, polling place availability, early voting access, voter registration rules, and ballot drop box policies. Advocates on different sides make empirical claims about the effects of these policies on voter participation and fraud prevention that researchers have studied extensively. Understanding what the research actually shows about the effects of specific voting rules on voter turnout and on fraudulent voting provides a basis for evaluating these debates on their merits. Voter ID laws, which require voters to present identification before casting a ballot, have been enacted in most states with varying requirements. Research on the effects of voter ID laws on voter turnout has been extensively conducted but has produced somewhat inconsistent findings, driven partly by methodological differences and partly by variation across the specific laws studied. Studies that use pre-post designs comparing turnout before and after voter ID law implementation tend to find smaller effects than studies that compare states with different requirements. Research published in peer-reviewed journals finds that strict photo ID laws, which require a current photo ID and offer limited alternatives, are associated with reduced turnout among racial and ethnic minority voters, young voters, and low-income voters, who have lower rates of qualifying ID possession. The population without qualifying ID is documented in research. Studies of ID possession rates find that a substantial proportion of Americans, ranging from 10 to 25 percent depending on jurisdiction and ID type required, lack qualifying government-issued photo ID. Those without ID are disproportionately elderly, low-income, Black, Latino, and young adults who have not yet established the residential and legal documentation that ID issuance requires. Free ID programs intended to make ID available to those who lack it have been studied and found to reach smaller proportions of the eligible population than advocates anticipated, partly due to administrative barriers. Research on the frequency of in-person voter fraud, which voter ID laws are specifically designed to prevent, finds consistently that this form of fraud is extremely rare. Studies using administrative data including voter files, court records, and reported fraud cases find confirmed cases of in-person impersonation fraud, the only type that voter ID requirements would prevent, numbering in the low dozens nationally across elections that involve hundreds of millions of votes cast. This finding does not necessarily argue against all voter ID requirements, which could serve other purposes including public confidence in elections, but it does undermine the fraud prevention rationale when fraud rates are this low. Early voting access, including in-person early voting and no-excuse absentee voting, has expanded in many states over the past two decades. Research on early voting and turnout finds positive but modest effects on overall participation, with larger effects for individuals with scheduling constraints including workers with inflexible schedules and elderly individuals for whom election day voting is physically difficult. Research on the composition of early voters finds that early voting is used by voters across partisan and demographic lines, rather than primarily benefiting one political party as sometimes claimed. Polling place changes, including consolidations that reduce the number of locations and relocations that change where voters go, affect the travel burden required for in-person voting. Research on polling place changes and voter turnout finds that reductions in polling place availability are associated with reduced turnout, with effects concentrated in communities that lose local polling places and must travel farther. Research on the effects of polling place changes in specific elections finds that minority-majority communities have experienced disproportionate reductions in polling place availability following the Supreme Court's 2013 decision in Shelby County v. Holder, which limited the preclearance requirements of the Voting Rights Act. Automatic voter registration, which registers eligible citizens automatically when they interact with government agencies unless they opt out, has been adopted in an increasing number of states. Research on states that have implemented automatic registration finds increases in registered voters and modest increases in turnout compared to the previous registration system. The effects are larger for younger voters and for voters who move frequently, groups that are less likely to be registered under traditional opt-in systems. The research on voting access is complex and context-dependent, but several findings are consistent: strict voter ID requirements with limited alternatives disproportionately affect certain demographic groups, in-person voter fraud is extremely rare, and policies that reduce the practical burden of voting tend to modestly increase participation. These findings do not resolve the political and legal debates about voting policy, which involve constitutional interpretation and value judgments about how to balance access and security, but they provide empirical grounding for evaluating specific claims made in these debates.