WASHINGTON - Earlier this year, voting rights advocates foresaw a cloud over this year's election because new voting laws in Republican-led states tightened the rules for casting ballots and reduced the time for early voting.

But with the election less than a month away, it's now clear those laws will have little impact. A series of rulings has blocked or weakened the laws as judges -- both Republicans and Democrats -- stopped measures that threatened to bar legally registered voters from polling places.

"Courts see their role as the protectors of the core right to vote," said Ned Foley, an election law expert at Ohio State University.

The laws were the product of a Republican sweep in the 2010 election. The GOP took full control in such states as Wisconsin, Pennsylvania, Ohio and Florida, and soon adopted changes in their election laws.

Some states told registered voters they must show a current photo identification, such as a driver's license, even if they did not drive. Others, including Florida and Ohio, reduced the time for early voting or made it harder for college students to switch their registrations.

Republicans defended the laws as protection against fraud. But advocates for increased access to the polls cast them as "voter suppression" laws that could prevent tens of thousands of poor and elderly voters, racial minorities and students from casting ballots. And Democrats, who can usually count on support from these voters, worried that the laws could even sway the outcome in the presidential race if it were close in key states.

The Constitution gives states the power to set the rules for elections, and judges usually uphold regulations adopted by state legislatures. But this year, judges took a more skeptical view.

State judges in Wisconsin and Pennsylvania blocked strict new photo ID laws from taking effect.

Ohio and Florida

And federal judges pressed Ohio and Florida to restore most of the early voting days that were cut under new laws. On Tuesday, Ohio Secretary of State Jon Husted announced he will appeal to the U.S. Supreme Court.

Another federal judge in Ohio said the state must count the ballots of voters who go to the right polling place but are sent to the wrong table for their precinct. Four years ago, 14,000 votes were lost for that reason.

A second federal judge set aside part of the Florida law that had prevented groups such as the League of Women Voters from registering new voters.

"It's been a remarkable series of victories," said Wendy Weiser, a lawyer for the Brennan Center for Justice, a liberal advocacy group that has opposed the new restrictions.

Most voters support voter ID laws, according to opinion surveys. Pennsylvania Secretary of State Carol Aichele said her state's photo ID law was "on track to be fully implemented in future elections. [It] is designed to preserve the integrity of every vote by doing what we can to make sure each voter is who they claim to be."

None of the rulings this year conclude that photo ID laws are unconstitutional. Rather, the judges said that if states plan to enforce such a new rule, they must ensure that people legally registered to vote -- including those who are old and do not drive -- can easily obtain the identification they need.

Pennsylvania

The Pennsylvania Supreme Court, which has three elected Republicans and three Democrats, said it would allow "no voter disenfranchisement" under the state's new voter ID law. And on that basis, a state judge decided last week that it could not be enforced this year. The court was told that hundreds of thousands of Pennsylvania's registered voters did not have the kind of photo ID card that would allow them to vote.

Texas

In a Texas case, federal judges focused on the difficulty of obtaining the right photo ID card from a state motor vehicle office. Because about a third of Texas counties do not have such an office, thousands of legal voters who do not drive faced the prospect of finding a way to travel more than 200 miles round trip to obtain ID cards, the judges said.

Rick Hasen, a law professor at the University of California, Irvine, said many of the rulings might not stand for long. "The victories over voter ID laws are likely to be short-lived," he said.