An Illinois judge has ruled that Donald Trump engaged in insurrection and has barred him from the state's primary ballot - though she put the ruling on hold pending an appeal.
Two other states - Colorado and Maine - have removed Mr Trump from their primary ballots for violating a 14th Amendment "insurrection" clause.
The final outcome will likely be decided by the US Supreme Court.
Illinois' primary election is scheduled for 19 March.
Early voting in the primary has already begun. Mr Trump - the front-runner Republican presidential candidate - will remain on the ballot until at least Friday while he has time to appeal against the order.
Cook County circuit judge Tracie Porter agreed with voters who argued Mr Trump had violated the US constitution's 14th Amendment because of his role in the 6 January Capitol riot.
It comes after Colorado's Supreme Court barred Mr Trump from appearing on the Republican primary ballot in December, arguing Mr Trump's actions during the 2021 Capitol riot amounted to insurrection.
In her ruling, Judge Porter called Colorado's rationale "compelling". She argued the state's Board of Elections was wrong to reject a previous bid to kick Mr Trump off the ballot.
"The Illinois State Board of Election shall remove Donald J Trump from the ballot for the General Primary Election on March 19, 2024, or cause any votes cast for him to be suppressed," she said.
A Trump spokesperson has called the ruling "unconstitutional" and vowed to appeal against it.
"The Soros-funded Democrat front-groups continue to attempt to interfere in the election and deny President Trump his rightful place on the ballot," the spokesperson said.
Mr Trump has already appealed against the Colorado case to the Supreme Court.
The top court heard arguments in the case earlier this month, appearing sceptical of Colorado's decision to ban Mr Trump from the ballot.
The legal challenge hinges on a Civil War-era constitutional amendment that bans anyone who has "engaged in insurrection or rebellion" from holding federal office.
But Supreme Court justices have asked tough questions of those representing Colorado voters in favour of banning Mr Trump.
Conservative Justice Brett Kavanaugh asked if there could be a "disenfranchising effect" if voters were not allowed to decide for themselves whether they wanted Mr Trump as president.
The Illinois judge's ruling comes after the Supreme Court agreed on Wednesday to hear yet another case involving Mr Trump. The 6-3 conservative majority court will decide whether the former president has immunity shielding him from a lawsuit over his attempts to overturn the 2020 election.