Interactive map: Does same-day registration affect voter turnout in the U.S.?

Nationally, some experts say policies governing the voting process in the United States prevent eligible voters from getting to the polls on Election Day.

After the Supreme Court overturned a key part of the Voting Rights Act, officials in North Carolina grappled with the passage of a new voter ID law and a reversal of many voting procedures civil rights leaders spent years trying to win.

“This is our Selma,” Rev. William Barber, a Protestant minister and political leader in the state, told PBS NewsHour. “We’re talking about taking away rights that people have utilized in elections, some since 2000.”

Other voting policies pose their own set of challenges for officials, such as same-day registration, a procedure that allows residents of those states to register to vote on Election Day right before casting their ballots.

The majority of states still require voters to register two to four weeks before an election, but 13 states currently offer same-day voter registration.

Using data from the United States Election Project, the map above shows the voter turnout rates from the total ballots counted among the voting-eligible population in each state in the 2014 general election. The larger dots represent a higher voter turnout rate. The states with same-day registration policies are represented by the blue dots.

Supporters of such same-day voter registration say that the policy helps increase voter turnout, particularly among racial minorities that may be otherwise disenfranchised from voting.

North Carolina began same-day registration in 2007. African-American voters made up about 35 percent of same-day registrants in the state, although they comprise only 22 percent of the state’s general electorate.

Sarah Walton of the League of Women Voters of Maine, another state that has same-day registration, says the policy “provides important safeguards for elections, helps to increase voter participation and makes sure that every eligible voter has an opportunity to participate.”

In Wisconsin, Milwaukee Mayor Tom Barrett said the policy is “one of the major reasons that Wisconsin has among the highest democratic participation in the nation.

Critics say that same-day registration has a negligible effect on voter turnout and can make it more difficult to verify voters’ identities or lead to voter fraud.

During the early voting period of the 2012 election in North Carolina, 2,144 same-day ballots were cast by voters whose addresses couldn’t be verified after the election.

View PBS NewsHour’s full report on North Carolina’s battle over voter ID laws: