After warning for years that Donald Trump posed an existential threat to American democracy, two constitutional scholars proposed a possible solution over the summer to keep him from regaining power: Trump, they argued, could be banned from holding office under an obscure provision of the 14th Amendment.

The push by former U.S. Court of Appeals judge J. Michael Luttig, a conservative, and Harvard professor Laurence H. Tribe, a liberal, was considered a long shot. But on Tuesday, it was unexpectedly validated by the Colorado Supreme Court, which ruled that Trump was ineligible for the state’s primary ballot because he had engaged in an insurrection.

Tribe and Luttig both cheered the precedent-setting decision, which the Trump campaign has vowed to appeal and which is almost certain to be taken up by the U.S. Supreme Court. But whatever the future of the case, constitutional scholars say it poses some of the thorniest and most consequential questions for American democracy of any in recent years.

Many constitutional scholars say the Colorado decision may be legally sound, but to apply it would be fraught politically, especially in a country so deeply divided and mistrustful of democratic institutions.

Taking Trump’s name off the ballot through a legal process would prevent him from returning to the White House, where he has threatened to suspend the Constitution and to use the levers of government to enact vengeance on his rivals. It would also prevent voters from rendering their own verdict on him.

“I believe in democracy,” said University of Chicago law professor Tom Ginsburg, “and I don’t think there’s a substitute for letting the people vote.”

Ginsburg co-wrote a 2021 article on legal provisions around the world that have disqualified candidates from office. He found that barring a political leader from the ballot is “a paradoxical tool that works best when it’s least needed, used against unpopular candidates that wouldn’t win anyway,” he said in an interview.

Trump, by contrast, is the runaway polling leader in the Republican primary field and is even or better with President Biden in hypothetical general election matchups. Given Trump’s popularity in the GOP, a court-imposed ban could produce a backlash that would further weaken many Americans’ faith in institutions, Ginsburg said.

Even some of Trump’s fiercest political critics have echoed that view. Chris Christie, the former New Jersey governor and federal prosecutor, has said he is running for president to stop Trump from gaining another term in office. But Christie lambasted the Colorado Supreme Court’s decision, saying it would “cause a lot of anger” if voters were not able to render a judgment on Trump.

“I do not believe Donald Trump should be prevented from being president of the United States by any court,” Christie told a crowd at a New Hampshire town hall hours after the decision was made public. “I think it’s bad for the country.”

The Colorado judges ruled by a margin of 4-3 that Trump is ineligible to run for president because he engaged in insurrection. Section 3 of the 14th Amendment, which was adopted three years after the end of the Civil War, barred people from office if they swore an oath to the Constitution and then engaged in insurrection. The measure was meant to keep former Confederates from returning to power. It has been used to disqualify candidates before, but only sparingly, and never with one with a following like Trump’s.

“President Trump did not merely incite the insurrection,” the majority of judges concluded. “Even when the siege on the Capitol was fully underway, he continued to support it by repeatedly demanding that Vice President Pence refuse to perform his constitutional duty and by calling Senators to persuade them to stop the counting of electoral votes. These actions constituted overt, voluntary, and direct participation in the insurrection.”

The three dissenters each had different reasoning. One of them, Justice Carlos Samour Jr., said he was “disturbed about the potential chaos wrought by an imprudent, unconstitutional, and standardless system in which each state gets to adjudicate Section Three disqualification cases on an ad hoc basis.”

Trump campaign spokesman Steven Cheung has called the decision “completely flawed” and predicted that, upon appeal, U.S. Supreme Court justices “will quickly rule in our favor and finally put an end to these un-American lawsuits.”

The U.S. Supreme Court has traditionally aimed to steer clear of presidential politics, though there have been notable exceptions. Most prominently, the court weighed in to halt a crucial recount underway in Florida following the 2000 election contest between Al Gore and George W. Bush, effectively cementing Bush’s victory.

Conservative legal scholars William Baude and Michael Stokes Paulsen laid much of the intellectual groundwork for applying Section 3 to Trump’s candidacy in a recent article in the University of Pennsylvania Law Review.

Luttig, who referenced their work and co-wrote with Tribe a piece for the Atlantic in August that helped to galvanize interest in the 14th Amendment, told Colorado Public Radio on Wednesday that the state Supreme Court ruling “was masterful and it is unassailable.”

He also said the U.S. Supreme Court must review the case according to the law, independent of any political considerations. “This is not politics,” Luttig said. “It is the Constitution that will disqualify the former president if he is disqualified.”

Others agreed. While it is impossible to ignore the political fallout of the legal cases, “the courts should act without any consideration of the political implications of their decisions,” said Mark Graber, a University of Maryland constitutional law scholar who this year published a book on the history of the 14th Amendment, “Punish Treason, Reward Loyalty: The Forgotten Goals of Constitutional Reform After the Civil War.”

Key to the 14th Amendment is that “there are limits to the democratic process in the name of democracy,” added Graber, who wrote an amicus brief in the Colorado case arguing that a president of the United States is covered under Section 3. Trump’s lawyers have argued that a president is exempt, and a lower Colorado court had accepted that view.

The Colorado Supreme Court ruling came as courts in other states have rejected attempts to knock Trump off the ballot on 14th Amendment grounds. Should the U.S. Supreme Court decide to review the Colorado decision, it is likely that the high court would issue a ruling that would apply nationwide.

The 14th Amendment challenge is far from the only legal fight that Trump is engaged in as the presidential primary season kicks off next month. He also faces charges in four criminal cases, as well as civil suits. Next year, the presidential campaign and Trump’s various legal cases are expected to play out simultaneously in a way that has no precedent in American history.

The legal system is meant to be independent of politics. But scholars say it has become increasingly difficult to disentangle the two.

“We are stuck in a conundrum between what the best reading of the law is and the much more complicated high politics of how that law should be enforced,” said Stephen Vladeck, a professor at the University of Texas at Austin School of Law.

Two of the criminal cases against Trump relate directly to his attempts to overturn the 2020 election. Trump, Vladeck said, is “embroiled in massively important novel criminal and civil litigation that is in many ways about his formal and practical eligibility to run for that office in the first place.”

Some legal experts worried that the Colorado decision would be seen as politically motivated, a charge that Trump himself has made repeatedly since the decision was issued. All seven state Supreme Court justices were initially appointed by Democratic governors.

“There’s a tendency on the part of people who think Trump is a problem to embrace this as a shortcut,” said Rick Esenberg, president and general counsel of the Wisconsin Institute for Law & Liberty.

Esenberg considers himself a “never Trump” Republican, but nevertheless disagrees with the Colorado ruling, arguing that Trump’s speech to his supporters before the Capitol riot on Jan. 6, 2021, constitutes protected speech.

If Trump is found ineligible based on what Esenberg deemed “an aggressive interpretation of terms like insurrection,” such decisions “become part of the political arsenal that both parties will deploy, and none of us should want that.”

Kim Lane Scheppele, a professor of sociology and international affairs at Princeton University, said other countries make it easier to remove candidates from the ballot. Many European nations, she said, disqualify parties that do not pledge to uphold their constitutions. Trump went further, she noted, directly threatening the U.S. constitutional order.

“The legal arguments are strong, and so the only question is whether the U.S. Supreme Court will have the political will to uphold the Colorado Supreme Court,” she said.

Given the unprecedented nature of Trump’s actions to subvert the 2020 election, the Colorado decision underscores “a uniquely uncomfortable moment for American democracy,” said Richard L. Hasen, a UCLA law professor.

But that moment could become even more uncomfortable if the Supreme Court delays weighing in on Trump’s qualification to appear on the ballot. With the Colorado primary coming up on March 5 and Iowa voters set to set to kick off the nominating process with a caucus on Jan. 15, Hasen said the court must resolve the issue sooner than later.

“Republican primary voters need to know what candidates are eligible,” he said. “A speedy resolution is important for democracy.”