Same-day registration (SDR) — sometimes called Election Day registration — lets eligible citizens register and vote in a single trip to the polls, typically with proof of identity and residence. More than twenty states plus the District of Columbia offer some form of SDR; the rest require registration anywhere from a few days to a month before Election Day.
Supporters point to consistently higher turnout in SDR states, especially among young voters, renters, and people who move frequently. They argue that pre-registration deadlines disenfranchise voters whose interest peaks in the closing weeks of a campaign — exactly when registration windows have already closed in many states.
Opponents argue SDR strains poll workers, complicates same-day verification, and increases the risk of fraudulent or erroneous registrations being processed under time pressure. They prefer in-advance registration with provisional ballots as a backstop for late registrants and emphasize the importance of stable voter rolls before Election Day.