In a victory for the Obama administration, a federal court has rejected a new law requiring Texans to present photo identification before being allowed to vote.

It was the latest skirmish in a nationwide battle on voting rights that has taken on new urgency in an election year. State legislatures have passed a flurry of new voting legislation since 2010, prompting a backlash from voting rights advocates and Democrats who suspect a partisan motive. Almost all of the laws have been crafted by Republican-controlled legislatures, and critics say they put an unwarranted burden on poor, minority, student and elderly voters -- groups who are more likely to vote Democratic.

A three-judge federal court backed that criticism on Thursday, ruling unanimously that the Texas law imposes "strict, unforgiving burdens on the poor" by forcing them to obtain identification that many of them lack. State Attorney General Greg Abbott vowed to appeal the decision.

Texas is no stranger to voting controversies: earlier this week, a separate three-judge panel ruled that new congressional maps drawn by the Republican-controlled state legislature discriminated against minorities and therefore violated the Voting Rights Act. Texas Governor Rick Perry has been a vocal opponent of the Voting Rights Act, arguing that its requirement that the federal government preclear new voting procedures in certain counties is outdated and burdensome.

Challenges to new voting laws have produced mixed results. On Wednesday, U.S. District Judge Robert L. Hinkle sided with opponents of a new Florida voting law by saying he would toss out new restrictions on groups that seek to register voters. The Florida League of Women voters had sued the state after suspending its registration drives, saying the new law's penalties were too onerous.

In Pennsylvania, a judge declined to intervene on a controversial new law that, like the Texas law, requires voters to present a government-approved form of photo identification at the polls. 

And South Carolina is fighting the federal government as it seeks to preserve its new voter ID law, with a lawyer for South Carolina arguing on Monday that having a systematic way to identify eligible voters was simply "common sense," according to the Washington Post. 

"A disproportionate number of those individuals are members of racial minority groups," Bradley Heard, a Justice Department lawyer, said in defending why the Justice Department had refused to clear South Carolina's new law, the first time in decades it has refused to clear a new state voting law.