In more than two hours of arguments, both conservative and liberal justices raised questions of whether Trump can be disqualified from being president again because of his efforts to undo his loss in the 2020 election, ending with the Jan. 6, 2021, attack on the U.S. Capitol.

The primary concern was whether Congress must act before states can invoke a constitutional provision that was adopted after the Civil War to prevent former officeholders who “engaged in insurrection” from holding office again. There also were questions about whether the president is covered by the provision.

Without such congressional legislation, Justice Elena Kagan was among several justices who wanted to know “why a single state should decide who gets to be president of the United States.”

Eight of the nine justices suggested that they were open to at least some of the arguments made by Jonathan Mitchell, Trump’s lawyer at the Supreme Court. Trump could win his case if the court finds just one of those arguments persuasive.

Only Justice Sonia Sotomayor sounded like she might vote to uphold the Colorado Supreme Court ruling that found that Trump “engaged in insurrection” and is ineligible to be president. The state court ruled Trump should not be on the ballot for the state’s Republican primary on March 5.

In another sign of trouble for the Colorado voters who sued to remove Trump from the ballot, the justices spent almost no time talking about whether Trump actually “engaged in insurrection” following the 2020 election.

Lawyer Jason Murray, representing the voters, pressed the point that Trump incited the Capitol attack to prevent the peaceful handover of power “for the first time in history.”

Mitchell argued that the Capitol riot was not an insurrection and, even if it was, Trump did not participate.

The case marks the first time the justices are considering Section 3 of the 14th amendment.

It sets up precisely the kind of case that the court likes to avoid, one in which it is the final arbiter of a political dispute.

Chief Justice John Roberts worried that a ruling against Trump would prompt efforts to disqualify other candidates, “and surely some of those will succeed.”

Trump’s lawyers argue that the amendment can’t be used to keep Trump off the ballot for several reasons.

For one thing, they contend the Jan. 6 riot wasn’t an insurrection, and even if it was, Trump did not participate. The wording of the amendment also excludes the presidency and candidates running for president, they say. Even if they’re wrong about all of that, they argue that Congress must pass legislation to reinvigorate Section 3.

The lawyers for Republican and independent voters who sued to remove Trump’s name from the Colorado ballot counter that there is ample evidence that the events of Jan. 6 constituted an insurrection and that Trump incited it. They say it would be absurd to apply Section 3 to everything but the presidency or that Trump is somehow exempt. And the provision needs no enabling legislation, they argue.

A definitive ruling for Trump would largely end efforts in Colorado, Maine and elsewhere to prevent his name from appearing on the ballot.

A decision upholding the Colorado decision would amount to a declaration from the Supreme Court that Trump did engage in insurrection and is barred by the 14th Amendment from holding office again. That would allow states to keep him off the ballot and imperil his campaign.

The justices could opt for a less conclusive outcome, but with the knowledge that the issue could return to them, perhaps after the general election in November and in the midst of a full-blown constitutional crisis.

Trump is separately appealing to state court a ruling by Maine’s Democratic secretary of state, Shenna Bellows, that he was ineligible to appear on that state’s ballot over his role in the Capitol attack. Both the Colorado Supreme Court and the Maine secretary of state’s rulings are on hold until the appeals play out.

The court has signaled it will try to act quickly, dramatically shortening the period in which it receives written briefing and holds arguments in the courtroom.

People began lining up outside the court on Wednesday hoping to snag one of the few seats allotted to the public. “This is a landmark decision and I want to be in the room where it happened, to quote ‘Hamilton,’” said Susan Acker of Cincinnati, Ohio, who was in line with two friends.

The issues may be novel, but Trump is no stranger to the justices, three of whom Trump appointed when he was president. They have considered many Trump-related cases in recent years, declining to embrace his claims of fraud in the 2020 election and refusing to shield tax records from Congress and prosecutors in New York.

Before the Supreme Court is even finished deciding this case, the justices almost certainly will be dealing with another appeal from Trump, who is expected to seek an emergency order to keep his election subversion trial on hold so he can appeal lower-court rulings that he is not immune from criminal charges.

In April, the court also will hear an appeal from one of the more than 1,200 people charged in the Capitol riot. The case could upend a charge prosecutors have brought against more than 300 people, including Trump.

The court last played so central a role in presidential politics in its 5-4 decision that effectively ended the disputed 2000 election in favor of George W. Bush.

Justice Clarence Thomas is the only member of the court who also took part in Bush v. Gore. Thomas has ignored calls by some Democratic lawmakers to step aside from the case because his wife, Ginni, supported Trump’s effort to overturn the 2020 election results and attended the rally that preceded the storming of the Capitol by Trump supporters.