US Supreme Court hears Trump 14th Amendment case: What to know

The U.S. Supreme Court on Thursday is considering a historic challenge to former President Donald Trump's ability to seek the Republican presidential nomination under Section 3 of the 14th Amendment due to his actions around the Jan. 6, 2021, attack on the U.S. Capitol.

It will be the first time that Trump's status, or that of any presidential candidate, will be considered under this "insurrection" constitutional clause at the nation's highest court, and it is one of the largest presidential election cases heard by the high court since 2000, when they confirmed the election of President George W. Bush over Al Gore.

The landmark case began in September in Colorado, when a group of six Republican and unaffiliated voters represented by the watchdog group Citizens for Responsibility and Ethics in Washington (CREW) filed a challenge against Trump and Secretary of State Jena Griswold, a Democrat who oversees the primary election process in the state.

Their lawsuit centered on Section 3, a rarely-invoked, Civil War-era clause that states that someone isn't eligible for future office if, while they were in office, they took an oath to support the Constitution but then "engaged in insurrection or rebellion against the same, or [gave] aid or comfort to the enemies thereof," unless they are granted amnesty by a two-thirds vote of Congress.

Proponents of this theory claim it applies to Trump because of his actions after he lost the 2020 election but sought to reverse the results, including on the morning of Jan. 6. Trump maintains he did nothing wrong and notes that he was acquitted of insurrection by a majority of Republicans in the Senate in 2021.

Colorado's Supreme Court decided in December that Trump would be barred from their GOP primary ballot, ruling that he had "engaged in insurrection" on Jan. 6. They said that Secretary Griswold would commit a "wrongful act" under state election law if she placed his name on the list. The order was quickly appealed by the Colorado Republican party and Trump's legal team to the U.S. Supreme Court.

The case could have lasting implications on the upcoming 2024 general election cycle. It puts Trump (the Republican front-runner) and the justices (including three whom Trump himself named) face to face ahead of what's shaping up to be a consequential rematch between Trump and current President Joe Biden.

The Supreme Court justices are expected to consider some unprecedented constitutional questions during this case and will be confronted with debate over whether Trump engaged in insurrection on Jan. 6. There are sweeping ramifications for the court's reputation, public trust and ongoing litigation against Trump.

What is the Supreme Court deciding?

Did the Colorado Supreme Court rule correctly in ordering Trump is off of the 2024 presidential primary ballot under the 14th Amendment? Is it therefore a "wrongful act" under state election law for him to be placed on the ballot by the Secretary of State?

How will the case be heard?

The Supreme Court agreed in early January to hear this case, docketed as Trump v. Anderson, on Thursday.

After the court convened at 10 a.m. on Thursday, oral arguments were set to start around 10:20 a.m. The arguments are formally allotted 80 minutes total but are expected to exceed this time frame.

Trump's attorney will begin the hearing with an opening statement, followed by questioning from the justices. Next, each justice is called on in order of seniority to have an uninterrupted opportunity to question counsel. This process will replicate for the legal counsel of the Colorado voters and Secretary of State Griswold's representation. The arguments will end with rebuttal by one of Trump's attorneys.

The case will be submitted at the conclusion of oral arguments. The court is not expecting to issue an opinion on the case immediately, though there is a non-binding deadline for a decision: March 5, when Colorado will hold their 2024 primary election.

Who is representing each side?

Trump will be represented by Jonathan F. Mitchell, a former clerk to Justice Antonin Scalia and a former Texas solicitor general who is credited with devising SB8, Texas' novel anti-abortion law which deputized everyday citizens to bring suits against anyone involved with the procedure. He has previously argued cases before the Supreme Court and has been on the law school faculties of Stanford University, the University of Texas, the University of Chicago and George Mason University.

The Colorado voters who sued to have Trump removed from the ballot will be represented by Jason C. Murray, a Harvard Law graduate and former clerk to Justice Elena Kagan and to Justice Neil Gorsuch, while he was on the 10th Circuit. Murray has extensive trial lawyer experience.

Colorado Secretary of State Griswold will be represented by the state Solicitor General Shannon W. Stevenson, a Duke University law graduate and former appeals court clerk who has a prestigious career in Colorado state law.

Central arguments

The hearing will likely address a number of disputed questions, including whether Section 3 is considered "self-executing" -- meaning, if elections officials wouldn't need special permission from lawmakers to disqualify Trump from the ballot -- the precise application and definition of the "officer" language in the provision, the definition of an insurrection and, most importantly: the application of Section 3 to a presidential candidate.

How did the case play out in Colorado?

The Supreme Court is the final stop in Trump v. Anderson's monthslong journey from a Denver district court.

After the Colorado voters filed their lawsuit in September, a blockbuster five-day evidentiary hearing starting on Oct. 30 was the first time that Section 3 was tried in court against a candidate for the U.S. presidency -- and the first legal test of escalating efforts to keep Trump off GOP primary ballots during the 2024 election.

CREW President Noah Bookbinder has said that his organization brought its suit in Colorado because "it is necessary to defend our republic both today and in the future." Trump and his campaign have dismissed the 14th Amendment clause being used against him, calling it anti-democratic.

Ahead of the Colorado evidentiary hearing, both sides said this case was likely to be punted up to the U.S. Supreme Court.

District Judge Sarah B.Wallace ruled against the group of Colorado voters on Nov. 17, citing "competing interpretations" of the constitutional clause and a "lack of definitive guidance in the text or historical sources" in order to rule its application to Trump.

But she also issued a first-of-its-kind decision that Trump, or any presidential candidate, had engaged in insurrection.

Both the legal team for Trump and the group of Colorado voters then appealed to the Colorado Supreme Court over the lower court's ruling -- the voters over Wallace's final judgment and Trump over her ruling that he engaged in insurrection.

The state Supreme Court took up the case and on Dec. 6 they heard a two-hour hearing. The seven-justice court posed sharp questions central to the case, including on the definition of insurrection; whether the Capitol riot that occurred on Jan. 6 was an insurrection; and whether the "insurrectionist ban" applies to a U.S. president.

A four-justice Supreme Court majority decided on Dec. 19 that the former president "engaged in insurrection" and was thus disqualified from the primary ballot.

"President Trump's direct and express efforts, over several months, exhorting his supporters to march to the Capitol to prevent what he falsely characterized as an alleged fraud on the people of this country were indisputably overt and voluntary," the justices wrote in the majority.

"Moreover," they wrote, "the evidence amply showed that President Trump undertook all these actions to aid and further a common unlawful purpose that he himself conceived and set in motion: prevent Congress from certifying the 2020 presidential election and stop the peaceful transfer of power."

The predicted that the matter would wind up in Washington -- staying the ruling until Jan. 4, saying it would maintain the status quo pending any review from the nation's high court.

What happens to the outstanding 14th Amendment challenges following a Supreme Court ruling?

Dozens of similar challenges to Trump's 2024 candidacy -- filed by individual voters, former politicians, a current Republican presidential candidate and government oversight and watchdog organizations -- have been weighed by lower courts, election boards or secretaries of state over the past year across roughly 34 states.

Trump has been declared ineligible to participate in a state's primary process only twice: by the Colorado Supreme Court and Maine's secretary of state, though he is still on the ballot in both places as each challenge is pending appeal.

Maine was the second state to order Trump off their ballot, with Secretary Shenna Bellows issuing her decision on Dec. 28, a little over a week after Colorado's ruling. That order was appealed by Trump's team to the state's top trial court, which on Jan. 17 deferred ruling until after the Colorado case was settled at the Supreme Court, a ruling that still stands.

At least nine legal challenges related to the 14th Amendment are pending -- 11 total with the Maine and Colorado cases included.

A number of the outstanding challenges were brought by Republican write-in presidential candidate John Anthony Castro, who told ABC News on Tuesday that he has only five pending challenges, in Arizona, New Hampshire, New Mexico, South Carolina and West Virginia. There are also pending challenges in Wyoming, Illinois and Massachusetts courts. Another voter's challenge with the North Carolina State Board of Elections is also pending.

Castro said that his efforts are intended to serve as an insurance policy in the event that the U.S. Supreme Court dismisses the Colorado case on purely procedural grounds. In that case, he could still mount 14th Amendment challenges on merit-based issues, he believes.

If the Supreme Court rules on decisive questions, like that Trump engaged in insurrection, all of the pending challenges could be declared moot. But if the court rules on the case because of election scheduling or state-based election law, 14th Amendment challenges could ostensibly continue across states outside of Colorado.