Republican Secretary of State Brad Raffensperger on Wednesday called for amending the Georgia Constitution to ban noncitizens from voting, a prohibition already enshrined in a state law.

Raffensperger, who is facing several Republican challengers in next year’s election, said a constitutional amendment would prevent the possibility of noncitizens being allowed to vote in the future, either as a result of lawsuits or changes to state laws.

“Voting is a sacred responsibility for American citizens,” Raffensperger said during a press conference in the state Capitol. “Our main goal should be to increase confidence in our election integrity, and also our security of our elections. Noncitizen voting would accomplish the exact opposite.”

Allegations of noncitizens voting in Georgia elections are rare. Raffensperger said he’s seen “isolated cases” come before the State Election Board. In February, the board imposed a $500 fine on a woman who was not a U.S. citizen when she voted in Gwinnett County in 2012 and 2016.

Amending the Georgia Constitution would require passage by two-thirds of the state House and Senate, followed by approval of a majority of voters in a referendum.

It is common for politicians to push proposed constitutional amendments on hot-button issues in election years.

Senate Minority Leader Gloria Butler, a Democrat from Stone Mountain, said she didn’t see the need to amend the constitution when state law already prevents noncitizens from voting.

“I guess he’s looking for anything he can to improve his chances of being reelected. It may sound good to Republicans, but it’s not necessary,” Butler said.

Raffensperger is being challenged by Republicans including U.S. Rep. Jody Hice and former Alpharetta Mayor David Belle Isle, who have both attacked him over his management of Georgia’s presidential election. Democratic state Rep. Bee Nguyen is also running for secretary of state.

Raffensperger has said Georgia’s presidential election results were accurate and trustworthy. Three ballot counts showed that Democrat Joe Biden defeated Republican Donald Trump by about 12,000 votes.

But Raffensperger has been attacked by supporters of Trump’s conspiracy theories that the election was stolen, and the secretary of state faces a dicey Republican primary next year where he will be accused of being disloyal to the former president.

Raffensperger said he’s concerned that efforts in other states to allow noncitizen voting could spread. The Vermont Legislature recently allowed noncitizen voting in local elections in two municipalities, and similar legislation has been introduced in Illinois and New York City.