The ruling comes as the former US leader prepares to run for the presidency in 2024.

Trump is accused of inciting riots at the US Capitol Building in an effort to overturn the result after he lost the US election in 2020.

The ruling in Colorado sets up a likely showdown in the US Supreme Court, which has the final say on constitutional matters, to decide whether the frontrunner for the Republican nomination can remain in the race for the White House.

The Trump campaign has already said it will appeal to the US Supreme Court.

"The Colorado Supreme Court issued a completely flawed decision tonight and we will swiftly file an appeal to the United States Supreme Court and a concurrent request for a stay of this deeply undemocratic decision," Trump campaign spokesman Steven Cheung said in a statement Tuesday night.

What does this mean for Trump?

The Colorado Supreme Court, whose justices were all appointed by Democratic governors, has now removed Trump from the state's presidential primary ballot.

It means as it stands voters in Colorado wouldn't be able to choose Trump in the presidential election next year.

But the ruling does not prevent him from running across the rest of the US.

Colorado officials say the issue must be settled by 5 January, the deadline for the state to print its presidential primary ballots.

"A majority of the court holds that Trump is disqualified from holding the office of president under Section 3 of the 14th Amendment," the court wrote in its 4-3 decision.

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It marks the first time in history that Section 3 of the 14th Amendment has been used to disqualify a presidential candidate.

Dozens of lawsuits have been filed nationally to disqualify Trump under Section 3, which was designed to keep former Confederates from returning to government after the Civil War.

It bars from office anyone who swore an oath to "support" the Constitution and then "engaged in insurrection or rebellion" against it, and has been used only a handful of times since the decade after the Civil War.

The Colorado Supreme Court has overturned a ruling from a district court judge who found that Trump incited an insurrection before the Capitol riots on 6 January 2021, but said he could not be barred from the ballot because it was unclear that the provision was intended to cover the presidency.

The Colorado Supreme Court has said: "We do not reach these conclusions lightly.

"We are mindful of the magnitude and weight of the questions now before us. We are likewise mindful of our solemn duty to apply the law, without fear or favour, and without being swayed by public reaction to the decisions that the law mandates we reach."

Trump lost Colorado by 13 percentage points in 2020 and doesn't need the state to win next year's presidential election.

But the danger for the former president is that more courts and election officials will follow Colorado's lead and exclude Trump from must-win states.