Topeka ? After decades of laws being approved aimed at making it easier to vote, a number of restrictions to enter the voting booth will be in place for the 2012 election, and Kansas is at the forefront of that trend.

A new study found the changes will make it harder for more than 5 million eligible voters to vote.

The study, done by the Brennan Center for Justice at New York University School of Law, states that new laws requiring voters to show photo ID, prove citizenship by producing birth certificates and other measures have been passed in several states.

“This is the most significant cutback in voting rights in decades. More voters may be affected than the margin of victory in two out of the past three presidential elections,” said Michael Waldman, the Brennan Center’s executive director.

“In 2012 we should make it easier for every eligible citizen to vote. Instead, we have made it far harder for too many. Partisans should not try to tilt the electoral playing field in this way,” he said.

Changes are in store for Kansas voters.

During the last legislative session, Kansas legislators approved a bill suggested by Kansas Secretary of State Kris Kobach and signed into law by Gov. Sam Brownback, both Republicans, that will require Kansas voters to show a photo ID to vote. The new requirement will be in effect for the 2012 election.

The bill also has a requirement, taking effect in 2013, that anyone registering to vote for the first time in Kansas will have to provide proof of their U.S. citizenship, such as a birth certificate. But Kobach has said he will return to the Legislature in January and seek to move up that requirement to 2012.

Kobach, one of the national leaders on pushing for voter ID and proof of citizenship, said the Brennan Center study is flawed. “It’s not a valid number,” Kobach said of the center’s conclusion on how many voters could be affected. “It’s a completely bogus extrapolation.”

Kobach was referring to the assertion by the Brennan Center that 11 percent of U.S. citizens do not have a state-issued photo ID. That included 18 percent of people age 65 and older, and 25 percent of African-American voting-age citizens, according to the study.

Those figures are based on a national telephone survey conducted in 2006 by Opinion Research Corp., a nationally recognized polling firm.

Larry Norden, one of the study’s authors and deputy director of the Brennan Center, said those figures are still valid today and have been backed up by more recent surveys.

“Every study that I’m aware of has come up with the same findings,” Norden said.

Conservatives often cite a 2008 study by the Center for Democracy and Election Management at American University as proof that problems have been exaggerated.

In a survey of three states — Indiana, Maryland and Mississippi — about 1 percent of registered voters lacked a photo ID, that study found.

That study noted that the debate over ID of voters often is partisan. Republicans cite the threat of voter fraud to pass ID; Democrats say the photo ID requirement will mean some voters won’t be able to exercise their right to vote.

“The problem with both partisan sides of the debate is that there is little evidence that would allow each side to prove its case,” the study said. “The supporters of ID can point to few examples of multiple or false voting, and the opponents cannot identify voters who did not vote because they did not have a voter ID.”