Voters in South Dakota will soon be able to challenge other voters’ citizenship.

Republican Gov. Larry Rhoden signed legislation into law last week that authorizes challenges by individuals and election officials.

“We do a lot of things right in South Dakota, and our election integrity is something to be admired and emulated by other states,” Rhoden said in a news release.

The new law will not affect the June 2 primary election, because it won’t take effect until July 1, which is the regular effective date for new laws in the state.

State law already allows challenges to a voter’s registration up to the 90th day before an election, if a person is suspected of lacking South Dakota residency, voting in another state or being registered to vote in another state. The new law adds citizenship as a justification for a challenge.

Challenges may be filed by the South Dakota Secretary of State’s Office, the auditor in the county where the voter is registered, or a voter in the same county. The challenge must be in the form of a signed, sworn statement and must include what the law describes as “documented evidence.”

If a county auditor deems the challenge valid, registrants are given a chance to produce documentation verifying their registration is valid. If the auditor ultimately cancels the registration, the person may appeal to a court or their local county commission.

The Secretary of State’s Office, which oversees elections, requested the bill and testified in favor of it.

“If you find somebody who’s not a citizen and is trying to vote, then do something about it,” said Thomas Deadrick, deputy secretary of state, during a legislative committee hearing. “This would be a way to do something about it.”

Sen. Liz Larson, D-Sioux Falls, voted against the legislation. She raised concerns about the potential ramifications of voters challenging other voters’ citizenship, especially in the aftermath of federal agents’ fatal shootings of two U.S. citizens during immigration enforcement actions in Minnesota. “In today’s environment,” Larson said during a committee hearing, the bill is “adding fuel to the fire.”

Melissa McCauley, a lobbyist for the immigrant advocacy group South Dakota Voices for Justice, testified against the bill. She said it would add unnecessary layers of law and bureaucracy for election officials.

“There is no documented pattern of noncitizen voting, widespread residency fraud or double voting in South Dakota that current law cannot already address,” McCauley said.

The new law is one of several citizenship-focused voting measures approved by the Legislature in recent years. During the 2025 legislative session, lawmakers put language into state law clarifying that voters in South Dakota must be U.S. citizens, and they sent a question to the November 2026 ballot asking voters to put similar language in the state constitution. Lawmakers also increased penalties for voting illegally.

In 2024, South Dakota officials discovered and cancelled the voter registrations of 273 non-U.S. citizens. The registrants had answered “no” on their driver’s license applications when asked if they were citizens, but were registered to vote due to human error, according to the Secretary of State’s Office. Noncitizens can obtain a driver’s license or state ID if they are lawful permanent residents or have temporary legal status, and the driver’s license application form includes a voter registration section.

One of those 273 noncitizens cast a ballot, the Secretary of State’s Office said. That was during the 2016 general election.

Federal law prohibits noncitizens from voting in federal elections. Last month, the U.S. House of Representatives passed legislation that would require people to produce a passport or birth certificate in most cases to register to vote. South Dakota’s lone member of the House, Republican Dusty Johnson, voted in favor of the bill.

The legislation, titled the Safeguard American Voter Eligibility Act or SAVE Act for short, is pending in the Senate. President Donald Trump threatened Sunday to withhold his signature from other legislation until Congress sends the bill to his desk.