The Colorado Supreme Court took extraordinary steps on Tuesday to remove Donald Trump from the state's 2024 primary ballot in a ruling that was quickly condemned by Republican lawmakers and is now poised to be reviewed by the Supreme Court.

The 4-3 decision by Colorado's higher court was made in response to a lawsuit filed in September, Anderson v. Griswold, which argued that Trump should be disqualified as a candidate under the basis of the Fourteenth Amendment. Section 3 of the amendment states that anyone who "engaged in insurrection or rebellion" against the US Constitution cannot hold office.

The lawsuit's petitioners include six people: Norma Anderson, Michelle Priola, Claudine Cmarada, Krista Kafer, Kathi Wright, and Christopher Castilian.

All but two of the petitioners are Republican voters, according to the lawsuit. Wright and Castilian are unaffiliated, the lawsuit said.

That's per Colorado law, Donald Sherman told Business Insider. Sherman is the executive vice president of Citizens for Responsibility and Ethics in Washington (CREW), a watchdog group that helped file the lawsuit.

"Colorado law requires that, in order for a voter to challenge the placement of the candidate in the Republican presidential primary, that they be Republicans or unaffiliated voters," Sherman said in an interview. "So in order to have standing, they had to be Republicans."

But the petitioners aren't random Republican voters blindly plucked out of the Centennial State. Most have played a prominent role in politics or have been outspoken voices for their party.

The lead plaintiff, Anderson, 91, is a former state legislator who served as a Republican in Colorado's House of Representatives and state Senate.

"As Norma likes to say, she has been a Republican for longer than most of her lawyers have been alive," Sherman said.

Kafer is a professor and columnist for The Denver Post who voted for Trump in 2016 and 2020, according to Sherman. A month before the 2020 election, Kafer wrote a column explaining "why this never-Trumper is voting for Trump."

Priola, who hasn't played a role in state politics, is the wife of Kevin Priola, a current member of the state Senate who joined the Democratic Party in 2022, denouncing the January 6 riot and Republican Party's attempts to undermine the 2020 election results.

"I think for us and them, it was important that these weren't just any old Republicans, but these were people who had really unassailable bonafides in the party," Sherman said.

After the lawsuit was filed in September, the Colorado Republican Party condemned the legal move in a statement posted on X.

"Never-Trumpers, RINO's, & Democrats are colluding to block from accessing the 2024 Colorado Republican Primary Ballot," the statement said. "We won't let them get away with it without a fight."

Although state law dictated the political affiliations of the petitioners, Sherman added that the involved parties were also motivated to perform a civic duty.

"They have made clear that they believe it's important not just for constitutional accountability but to ensure that Republican voters in Colorado had a primary that had the utmost integrity and had only qualified candidates in it," he said. "That's one of the reasons why they brought this case, and it's one of the reasons why we and they are so thrilled at the court's judicious decision."