Objective. Early voter registration deadlines make voting more difficult for many American citizens. In an attempt to facilitate voting, several U.S. states now permit registration on election day, at the height of the campaign. This article examines the turnout effects of adopting election day registration (EDR) and other smaller reductions in closing dates. Methods. Primarily using the Current Population Study (1972-1996), we estimate the turnout advantage of EDR for citizens having low, middle, and high socioeconomic status. Results. The elimination of closing dates, through EDR, is predicted to produce about a 7-percentage-point turnout boost in the average state. Those having a high school education and middle incomes are expected to see the largest turnout gains, with the less educated and poorer citizens doing almost as well. No evidence is found to link the implementation of EDR to subsequent changes in the electorate's partisan balance. Conclusions. Even the most dramatic easing of voter registration costs has a modest effect on the total number of voters and little impact on the long-standing skew toward greater representation of those having higher status in the voting electorate of the United States.