The court cited a constitutional insurrection clause while giving the order.

In a landmark decision, the court ruled 4-3 that Trump is not an eligible candidate, reported BBC.

Interestingly, it is the first time that Section 3 of the US Constitution's 14th Amendment was used to disqualify a presidential candidate.

Tuesday's decision - which has been placed on hold pending appeal until next month - does not apply to states outside Colorado, BBC reported.

The ruling only applies to the state's primary election on 5 March, when Republican voters will choose their preferred candidate for president, though it could have an effect on the general election in November, the British media reported.

In the ruling, justices wrote as quoted by BBC: ""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 favor, and without being swayed by public reaction to the decisions that the law mandates we reach."

Meanwhile, former federal appellate judge and prominent conservative J. Michael Luttig described the Supreme Court's decision as 'unassailable'.

“The individual justices of the Colorado Supreme Court brought honor to their court as well to the state and federal judiciaries with their opinion tonight in this historic case,” Luttig told CNN, describing their "meticulous" efforts to address all the issues involved in the case.

“Their opinion is unassailable under the objective law of the federal constitution and section 3 of the 14th Amendment. The Supreme Court of the United States ought to affirm this decision today,” he added.

Republican National Committee Chairwoman Ronna McDaniel reacted to the decision and posted on X: " This irresponsible ruling will be appealed to the U.S. Supreme Court and our legal team looks forward to helping fight for a victory. The Republican nominee will be decided by Republican voters, not a partisan state court."

Republican presidential candidate Vivek Ramaswamy said he would pull out from the Colorado ballot if the state's Supreme Court does not allow the former president to contest.

"I pledge to withdraw from the Colorado GOP primary ballot until Trump is also allowed to be on the ballot, and I demand that Ron DeSantis, Chris Christie, and Nikki Haley do the same immediately - or else they are tacitly endorsing this illegal maneuver which will have disastrous consequences for our country," he posted on X.