Advocates for the poor, disabled and minorities said the bill would suppress voter participation and take the state backward in voting rights.
"Voting is a right, not a privilege. Government should be making it easier for voters to exercise their rights," said Victoria Middleton, the executive director of the state chapter of the American Civil Liberties Union.
Other groups joining her at the Statehouse included AARP, the League of Women Voters, the NAACP and Protection and Advocacy for People with Disabilities.
Its executive director, Gloria Prevost, said people with disabilities rely on others for transportation, and the bill would impede their access to a ballot box.
In January, the GOP-controlled House pushed the measure through on a party-line vote. It comes up for debate in the House today with the Senate's changes.
Republican legislators pushed the issue last year, but it died with the House and Senate unable to agree on a compromise.
Republicans say it's an issue of voter integrity. Democrats complain it would disenfranchise voters and harken back to Jim Crow-era laws meant to keep minorities from voting.
Currently, voters can show voter registration cards, which lack pictures, or driver's licenses. Under the measure, they would have to show either licenses, photo IDs issued by the Department of Motor Vehicles, passports, military IDs, or new voter registration cards that include photos.
About 178,000 voters in South Carolina don't have driver's licenses or DMV-issued photo IDs, according to the state Election Commission.