Maine’s Democratic secretary of state on Thursday removed former President Donald Trump from the state’s presidential primary ballot under the Constitution’s insurrection clause, becoming the first election official to take action unilaterally as the U.S. Supreme Court is poised to decide whether Trump remains eligible to continue his campaign.

The decision by Secretary of State Shenna Bellows follows a December ruling by the Colorado Supreme Court that booted Trump from the ballot there under Section 3 of the 14th Amendment. That decision has been stayed until the U.S. Supreme Court decides whether Trump is barred by the Civil War-era provision, which prohibits those who “engaged in insurrection” from holding office.

The Trump campaign said it would appeal Bellows’ decision to Maine’s state court system, and it is likely that the nation’s highest court will have the final say on whether Trump appears on the ballot there and in the other states.

Bellows found that Trump could no longer run for his prior job because his role in the Jan. 6, 2021 attack on the U.S. Capitol violated Section 3, which bans from office those who “engaged in insurrection.” Bellows made the ruling after some state residents, including a bipartisan group of former lawmakers, challenged Trump’s position on the ballot.

“I do not reach this conclusion lightly,” Bellows wrote in her 34-page decision. “I am mindful that no Secretary of State has ever deprived a presidential candidate of ballot access based on Section 3 of the Fourteenth Amendment. I am also mindful, however, that no presidential candidate has ever before engaged in insurrection.”

The Trump campaign immediately slammed the ruling. “We are witnessing, in real-time, the attempted theft of an election and the disenfranchisement of the American voter,” campaign spokesman Steven Cheung said in a statement.

Thursday’s ruling demonstrates the need for the nation’s highest court, which has never ruled on Section 3, to clarify what states can do.

While Maine has just four electoral votes, it’s one of two states to split them. Trump won one of Maine’s electors in 2020, so having him off the ballot there should he emerge as the Republican general election candidate could have outsize implications in a race that is expected to be narrowly decided.

That’s in contrast to Colorado, which Trump lost by 13 percentage points in 2020 and where he wasn’t expected to compete in November if he wins the Republican presidential nomination.

In her decision, Bellows acknowledged that the Supreme Court will probably have the final word but said it was important she did her official duty. That won her praise from a group of prominent Maine voters who filed the petition forcing her to consider the case.

“Secretary Bellows showed great courage in her ruling, and we look forward to helping her defend her judicious and correct decision in court. No elected official is above the law or our constitution, and today’s ruling reaffirms this most important of American principles,” Republican Kimberly Rosen, independent Thomas Saviello and Democrat Ethan Strimling said in a statement.