What evidence exists about the frequency and impact of noncitizen voting in U.S. federal elections?
Executive summary
Evidence assembled by election researchers, nonpartisan analysts and state audits shows that noncitizen voting in U.S. federal and statewide elections is illegal and—while it occasionally happens—occurs at vanishingly small rates that have not been shown to change federal outcomes [1] [2] 2024final.pdf" target="blank" rel="noopener noreferrer">[3]. High-profile claims that “millions” of noncitizens voted in recent elections are not supported by audits, peer-reviewed research reviews, or federal and state verifications, though partisan actors and some advocacy groups continue to press divergent narratives [1] [4] [5].
1. Legal baseline and the institutional safeguards that matter
Federal law and every state prohibit noncitizens from voting in federal elections, and a patchwork of registration checks, voter-roll maintenance, and prosecutions exist to detect ineligible voters—measures that scholars and election officials cite as a key reason noncitizen voting is rare [1] [2] [3]. Some local jurisdictions permit noncitizen voting in limited local contests, but these are explicitly confined to local rules and do not change the federal ban [1] [6].
2. What audits, studies and official reviews actually find about frequency
Multiple comprehensive reviews and audits—by academic teams, the Brennan Center, Migration Policy Institute, state secretaries of state, and recent federal verification exercises—report only isolated instances: examples include investigations that identified a handful to a few dozen suspected or confirmed noncitizen votes across millions of ballots reviewed, and state audits after 2024 returning “extremely rare” incidence rates [2] [7] [4]. The Brennan Center’s 2017 review of 23.5 million votes found just about 30 referrals for suspected noncitizen voting, illustrating the rarity scholars emphasize [2].
3. Measuring impact: how many noncitizen votes would matter?
Analyses that model hypothetical scenarios show that noncitizen turnout would need to be substantially larger—often many percentage points of the noncitizen population in key states—to alter presidential margins in 2024 in most states; only in a handful of places would relatively modest noncitizen turnout approach the margin of victory, and such turnout is not observed in audits [8]. Empirical evidence and postelection surveys from trusted sources like the Census and Pew focus on citizen turnout and do not find indications that noncitizen ballots shifted national results, and state reviews after 2024 found no coordinated campaigns to mobilize noncitizen voting that would be necessary to change outcomes [9] [7].
4. Where contested claims come from and why they spread
A small number of academic papers and survey artifacts dating back to the 2008–2010 era produced disputed estimates that have been amplified by partisan actors; social-media amplification and selective use of datasets have periodically resurrected inflated figures—claims that independent fact-checks and rapid-response analyses have shown to be misleading or based on small samples and measurement error [5] [6]. Conservative policy groups and some lawmakers have used administrative matches and partisan databases to argue for systemic problems, but even those datasets (and organizations’ own collections of prosecuted cases) document very few proven incidents relative to the scale of U.S. elections [6] [10].
5. Remaining uncertainties, methodological limits and the political stakes
Important methodological limits remain: survey misreporting, administrative matching errors (including DHS tools that can falsely flag citizens), uneven transparency across states, and the low base rate of incidents make precise incidence estimates difficult and susceptible to amplification [4] [7] [5]. Politically, allegations of widespread noncitizen voting have served as a rationale for restrictive laws and verification requirements—measures critics argue are disproportionate given the evidence and may impose burdens disproportionately on eligible voters—so motives and policy consequences must be weighed alongside the raw incidence data [2] [11].
Bottom line
The preponderance of credible evidence—from audits, academic reviews, nonprofit research and postelection state checks—concludes that noncitizen voting in federal elections is illegal, does occur rarely, and has not been demonstrated to change federal election outcomes; contested claims of mass noncitizen voting are not supported by the bulk of available, vetted data, even as data limitations and political incentives keep the debate active [1] [2] [4].