The state House is poised to pass a bill that would require Pennsylvanians to show photo identification before voting, set to take effect this year.
House Majority Leader Mike Turzai said the bill is about upholding a constitutional principle.
"It's 'one person, one vote,' and I don't think anybody should object to that long-held constitutional principle," said Turzai. "I think voter ID specifically reinforces the notion that each person is entitled to one vote in this country."
If passed and signed by the governor as expected, voter ID requirements would be in effect for this year's general election.
An overwhelming majority of Pennsylvanians recently polled support the measure, but House Democrats oppose the bill because they say it would discourage the elderly and minorities from filling out ballots.
Acceptable forms of voter ID would include a driver's license or non-driver's license from PennDOT, county and municipal employee ID, as well as ID from the federal government, a Pennsylvania accredited college or university, or a Pennsylvania care facility.
The state will issue free photo IDs to anyone without one, but critics contend some individuals would have to pay to get a new birth certificate.
Keesha Gaskins of the New York University School of Law said 11 percent of Americans who are eligible to vote do not have photo ID.
Gaskins said the "one person, one vote" argument is telling of the lack of evidence that voter fraud is a problem.
"We're now falling back on the idea of a principle to enact a law that actually restricts the vote, the vote of persons," Gaskins said.