Judge Tracie Porter issued her decision after a group of voters trying to remove Trump’s name from the primary ballot over the Jan. 6, 2021, attack on the U.S. Capitol sued to counter the election board’s unanimous rejection of its effort. The five voters argued that Trump is ineligible to hold office because he encouraged and did little to stop the Capitol riot and insurrection.

The case is one of dozens of lawsuits filed to remove Trump from the ballot, arguing he is ineligible due to a rarely used clause in the 14th Amendment prohibiting those who “engaged in insurrection” from holding office. The U.S. Supreme Court earlier this month signaled that it is likely to reject this strategy when it heard an appeal of a Colorado ruling removing Trump from the ballot there. Like the Illinois decision, that Colorado ruling is on hold until the appeal is finished.

Porter, in her 38-page ruling, wrote that the petition by the group of voters should have been granted because they had met their burden and the election board’s decision was “clearly erroneous.”

“This is a historic victory,” said Ron Fein, legal director of Free Speech For People and co-lead counsel in the case. “Every court or official that has addressed the merits of Trump’s constitutional eligibility has found that he engaged in insurrection after taking the oath of office and is therefore disqualified from the presidency.”

Trump campaign spokesman Steven Cheung issued a statement saying that “an activist Democrat judge in Illinois summarily overruled the state’s board of elections and contradicted earlier decisions from dozens of other state and federal jurisdictions. This is an unconstitutional ruling that we will quickly appeal.”

Porter said her order would be put on hold if the Supreme Court’s ruling is ultimately “inconsistent” with hers.