DES MOINES, Iowa (AP) — Secretary of State Matt Schultz renewed his push Thursday for a law requiring voters to show identification before they can cast ballots at polling places, but critics say such a measure isn't necessary and would lead to disenfranchisement.

Schultz made voter identification the key issue of his 2010 campaign and supported a similar bill last session that was approved 60-40 in the Republican-controlled House but never taken up in the Democratic Senate.

Sen. Jeff Danielson, a Cedar Falls Democrat and chairman of the State Government Committee, said there's no evidence voter fraud is a problem in Iowa or has ever affected the outcome of an election. Schultz's bill will go through his committee, but Danielson said he hasn't examined the bill closely and isn't sure whether it will receive a hearing.

"Our guiding principal is the safest, most secure, most efficient election system in the country without disenfranchising a single voter," Danielson said.

Schultz, a Republican, acknowledged Thursday that he didn't know how common voter fraud was in Iowa but said it was important to close potential loopholes.

"The real point of this law is to make sure you are who you say you are when you come to vote," he said.

Some have accused him of supporting a voter ID law because studies show that students, minorities and low-income people are less likely to have identification. Those groups tend to favor Democrats.

Ben Stone, executive director of the ACLU of Iowa, said the fact that Schultz can't point to instances of voter fraud indicates the measure is unnecessary.

"Unless there's a problem, there's really no point and certainly no justification for making it harder to vote," he said, adding that such a measure also could be unconstitutional.

Schultz said he wasn't trying to create barriers for voters and his plan would give people alternatives if they don't have identification.

The bill allows students to show a school ID and older people to sign an affidavit affirming their identity. It also would provide free state photo IDs, and allow a person with an ID to attest for someone without one.

"We're not trying to disenfranchise people or keep people from voting," Schultz said.

The law would not apply to absentee voting, although Schultz said he intends to address that too.

Danielson said laws already exist to protect against voter fraud. If a local elected precinct official believes somebody is committing identity fraud they have the legal obligation to ask for an ID.

He said instead of making it harder for people to vote, the state should be looking for ways to encourage greater participation in the political process.

"What's ironic about the secretary's crusade is most people choose not to vote," Danielson said.

House Speaker Kraig Paulsen, a Hiawatha Republican, didn't indicate he would push for Schultz's bill to be approved in the House.

"My hope is the Senate will pick up the voter ID bill we passed last year and if the secretary or the Senate has improvements they should amend it and send it back," Paulsen said.