Former president Donald Trump’s Republican presidential opponents are joining in his criticism of a Colorado Supreme Court ruling Tuesday that Trump could not appear on the ballot for the state’s presidential primary.

In a historic 4-3 decision Tuesday, the Colorado court ruled that Trump was disqualified under an 1868 provision of the Constitution that prevents insurrectionists from holding office, citing the Jan. 6, 2021, insurrection, when a pro-Trump mob overran the U.S. Capitol to stop the certification of Joe Biden’s electoral win.

Almost immediately after the Colorado Supreme Court issued its decision, Trump’s rivals in the GOP presidential primary weighed in, with most criticizing the ruling. The most fervent defense of Trump came from entrepreneur Vivek Ramaswamy, who claimed in a nearly 400-word statement that the Colorado decision was “what an *actual* attack on democracy looks like.”

Ramaswamy, who is polling at about 5 percent in Iowa, also vowed to withdraw from the Colorado GOP primary unless Trump was also allowed to appear on the ballot. He demanded that DeSantis, Christie and Haley “do the same immediately — or else they are tacitly endorsing this illegal maneuver which will have disastrous consequences for our country.”

Florida Gov. Ron DeSantis (R) did not mention Trump by name but suggested without citing evidence that the Colorado Supreme Court justices were politically motivated.

“The Left invokes ‘democracy’ to justify its use of power, even if it means abusing judicial power to remove a candidate from the ballot based on spurious legal grounds. SCOTUS should reverse,” DeSantis wrote in a post on X, formerly Twitter.

Former United Nations ambassador Nikki Haley, who has captured momentum in recent weeks and threatened to overtake DeSantis as the leading Republican alternative candidate to Trump, told reporters in Iowa on Tuesday that Trump should be defeated at the polls, not in the courts.

“I will tell you that I don’t think Donald Trump needs to be president. I think I need to be president. I think that’s good for the country,” Haley said. “But I will beat him fair and square. We don’t need to have judges making these decisions; we need voters to make these decisions.”

Former New Jersey governor Chris Christie (R), who has been one of Trump’s most vocal critics, said he got word of the decision while in a car on the way to a New Hampshire campaign event. Christie later told the audience he needed to read the full decision, but said it was “probably premature.”

“I do not believe Donald Trump should be prevented from being president of the United States by any court,” Christie said at the event. “On the principle, I don’t believe a court should exclude somebody from running for president without there being a trial and evidence that’s accepted by a jury that they did participate in insurrection. … I think it would cause a lot of anger in this country if people had the choice taken away from them. I would rather have them make the choice that he doesn’t deserve it.”

The only Republican presidential candidate to agree with the Colorado Supreme Court ruling was former Arkansas governor Asa Hutchinson, who has also been critical of Trump. Hutchinson, who did not qualify for the last two GOP primary debates, noted that he had raised this scenario during the first presidential debate in Milwaukee.

“The factual finding that he supported insurrection will haunt his candidacy,” Hutchinson wrote on X.

Trump holds a commanding lead over the GOP field, according to recent polls in Iowa and New Hampshire. Scores of GOP lawmakers rallied around Trump, issuing statements criticizing the Colorado ruling on Tuesday.

The former president railed against the decision Tuesday night in posts on his social media platform, Truth Social, quoting conservative news outlets that had defended him. He continued his tirade early Wednesday with several all-caps posts — including, “A SHAME FOR OUR COUNTRY!!!” and “A SAD DAY IN AMERICA!!!” — as well as a fundraising bid off the Colorado ruling.

White House press secretary Karine Jean-Pierre declined Wednesday to comment on the ruling.

“The president’s not involved. We’re not involved in this. This is a legal process,” she said.

Biden also declined to comment on the case when asked by reporters Wednesday, but said that Trump “certainly supported an insurrection.”

“Now whether the 14th Amendment applies, I’ll let the court make that decision,” Biden said.

The Colorado decision comes as courts in other states consider similar cases. If other states reach the same conclusion, Trump would have a difficult — if not impossible — time securing the Republican nomination and winning in November.

The decision is certain to be appealed to the U.S. Supreme Court, but it will be up to the justices to decide whether to take the case. Scholars have said only the nation’s high court can settle for all states whether the Jan. 6 attack on the U.S. Capitol constituted an insurrection and whether Trump is banned from running.

Patrick Marley and Azi Paybarah contributed to this report.