As many as 30 states are considering voter-identification legislation, according to the National Conference of State Legislatures. Thirteen - including Indiana, Georgia and Florida - now require photo identification. Sixteen ask for nonphoto ID.
In 2006, Gov. Ed Rendell vetoed a similar bill.
Rep. Babette Josephs (D., Phila.) has been among the most vocal critics of the effort in Pennsylvania. She has called the move an unabashed political effort by Republicans to disenfranchise poor, elderly, and minority voters.
"This bill is going to achieve exactly the opposite of making elections more fair," Josephs said. "It's going to shut out legitimate votes in an attempt to shut out fraudulent votes that don't exist."
The proposal's sponsor, Rep. Daryl Metcalfe (R., Butler), said the proposal was about nothing more than keeping state elections honest.
"Every illegally counted ballot cancels out the vote of a legitimate voter," Metcalfe said. "Photo IDs currently are needed to board a plane, enter federal buildings, and cash a check. Voting is equally important."
Numerous groups have joined the debate, including the nonpartisan County Commissioners Association of Pennsylvania.
Doug Hill, the association's executive director, said no county had reported even a suspicion of significant voter fraud.
"It just doesn't happen the way supporters are claiming it does," Hill said.
State figures show that of the nearly six million people who voted in Pennsylvania in the 2008 presidential election, just four were convicted of voter fraud.
Figures published periodically by New York University's School of Law suggest voter-identification bills have a more significant impact on minorities: Black, Hispanic and Asian voters are 5 to 10 percent less likely to have the kind of identification necessary under such laws, according to a report published last month.
Groups lobbying against the legislation include the ACLU of Pennsylvania, the NAACP, the Mental Health Association of Southeastern Pennsylvania, and more than 30 others.
"Many of those people my organization represents are homeless and simply do not have ID," said Frances Hazam, a consumer advocate for the Mental Health Association of Southeastern Pennsylvania.
Andy Hoover, the ACLU's legislative director, said the bill as written would have a disproportionate effect on minorities, the elderly, and people with disabilities.
"This bill is an expensive piece of legislation that would disenfranchise hundreds of thousands of Pennsylvanians who are eligible to vote but do not have the required ID," Hoover said.
House Majority Leader Mike Turzai (R., Allegheny) scoffed at such claims during the debate.
"Allegations that members of my caucus are attempting to shut out legally registered voters have no merit," Turzai said. "We have reports of thousands of false voter registrations during every big election cycle.
"There is simply no other way to ensure that those people who show up at the polls really are who they say they are."
Contact staff writer John Manganaro at 412-335-9281.