Last year, new voter ID laws passed in Kansas, Mississippi, Rhode Island and Wisconsin. In addition to Texas and South Carolina, Alabama and Tennessee tightened existing voter ID laws to require photo ID. Governors in Minnesota, Missouri, Montana, New Hampshire and North Carolina vetoed new photo ID laws.

This year, Pennsylvania enacted its own law and voting-rights groups who filed suit in an effort to stop it are appealing to the state Supreme Court. A hearing is scheduled for Sept. 13 in Philadelphia. The Republican administration of Gov. Tom Corbett says a U.S. Justice Department inquiry into the state's tough new voter identification law is politically motivated. The department is requesting the state's voter registration list, plus any database of registered voters who lack a valid photo ID that the law requires voters to show before their ballots can be counted.

In Wisconsin, a county judge ruled in July that the state's new photo ID law impairs the right to vote. In an appeal, Wisconsin Attorney General J.B. Van Hollen, a Republican, is arguing that the ID law doesn't impose an undue burden because voters can get free state ID cards.

Election administrators and academics who monitor the issue said in-person fraud is rare because someone would have to impersonate a registered voter and risk arrest. A report by the Brennan Center for Justice determined that new voting restrictions could suppress the votes of more than 5 million young, minority, low-income and disabled voters.

Also of interest: Longtime voter, 93, challenges id law.