ATLANTA — Gov. Brian Kemp signed legislation Tuesday that makes additional changes to Georgia's election laws ahead of the 2024 presidential contest in the battleground state, including defining probable causes for removing voters from the rolls when their eligibility is challenged.

Republican activists — fueled by debunked theories of a stolen election — have challenged more than 100,000 voters in the state in recent years. The activists say they are rooting out duplicate records and removing voters who have moved out of state.

The bill Kemp signed into law — SB 189 — lists death, evidence of voting or registering in another jurisdiction, a tax exemption indicating a primary residence elsewhere, or a nonresidential address as probable causes for removing voters from the rolls. Most controversially, it says the National Change of Address list can be considered, though not exclusively.

Supporters have said the probable cause definition would make the challenge process more difficult. Opponents have disputed that, saying the changes would enable more baseless attacks on voters that would overwhelm election administrators and disenfranchise legitimate voters. For example, people sometimes live at a place of business, which would be considered a nonresidential address. Officials with Georgia Secretary of State Brad Raffensperger’s office say there are more reliable types of information, such as driver’s license data, to confirm a voter’s eligibility.

The Georgia bill also allows challenges to be accepted and voters removed from the rolls up until 45 days before an election. That provision in part has prompted the threat of lawsuits from liberal groups because federal law says states and counties can’t make systematic changes to voting rolls within 90 days of a federal election.

The measure also says homeless people must use the county voter registration office as their address instead of where they live. Opponents have said that could make it harder for homeless citizens to cast ballots because their registered polling place might be far away.

Fair Fight Action, a voting rights group founded by former Democratic Georgia gubernatorial candidate Stacey Abrams, slammed the signing of SB 189, calling the measure a “voter suppression bill that emboldens right-wing activists in their efforts to kick Black and brown voters off the rolls.”

“By signing SB 189 to become law, Brian Kemp delivered a gift to MAGA election deniers,” the group said in a statement.

Andrea Young, executive director of the ACLU of Georgia, called the bill a “step back for voters' rights and voting access.”

"We are committed to protecting Georgia voters and will see the governor in court,” she said in a statement.

An email to a spokesman for the governor's office, Garrison Douglas, was not immediately returned.

The bill also grants access to Georgia’s ballot to any political party that has qualified for the presidential ballot in at least 20 states or territories. The change could bolster independent candidates such as Robert F. Kennedy Jr., whose campaign has spooked Democrats worried it could draw support away from President Joe Biden.

Other changes in the bill include removing Raffensperger from his ex-officio spot on the State Election Board. Kemp and Republican lawmakers had previously removed Raffensperger from his voting position on the board.

Many Republicans who believe debunked theories that former President Donald Trump was cheated out of Georgia’s 16 electoral votes in 2020 view Raffensperger as a particular enemy because the Republican secretary of state has forcefully defended the election results showing Biden won.

Raffensperger and some others had lobbied for Kemp, himself a former secretary of state, to veto the bill.

The bill, additionally, says that beginning July 1, 2026, the state can no longer use a kind of barcode called a QR code to count ballots created on the state ballot marking devices. That is how votes are counted now, but opponents say voters don’t trust QR codes because they can’t read them. Instead, the bill says ballots must be read using the text, or human-readable marks like filled-in bubbles, made by the machines.

The bill also requires counties to report the results of all absentee ballots by an hour after polls close. It also lets counties use paper ballots in elections in which fewer than 5,000 people are registered, though that change will not take effect until 2025.

Kemp on Tuesday vetoed a separate election bill that would ban political contributions by foreign nationals and impose additional registration requirements on agents of foreign principals. The governor noted that such donations are already prohibited by federal law, and he said some of the registration requirements were not intended by the bill's sponsor.