Donald Trump is expected to appeal the Colorado and Maine rulings banning him from primary ballots

By Nicholas Riccardi/AP

Former President Donald Trump on Tuesday is expected to appeal rulings from Colorado and Maine that ban him from the states' ballots, setting up a high-stakes showdown over a 155-year-old addition to the Constitution that bars from office those who “engaged in insurrection.”

Trump would appeal the Colorado Supreme Court ruling to the U.S. Supreme Court and the decision by Maine’s Democratic secretary of state to that state's Superior Court.

It would mark the first time the nation’s highest court could rule on Section 3 of the 14th Amendment, two sentences added to the Constitution after the Civil War to prevent Confederates from returning to their former government offices. The clause says that anyone who swore an oath to support the Constitution and then “engaged in insurrection” against it is no longer eligible.

The appeals come as tensions mount over rulings that could keep the 2024 Republican presidential front-runner off ballots, though both the Maine and Colorado rulings are on hold until the appeals end, and Trump technically remains on the primary ballots in both states.

On Tuesday morning, Denver police arrested a man who fled a car crash and ran into the Colorado Supreme Court building. Police said he pointed a gun at an unarmed security officer, getting the guard’s keys and access to the whole building, and fired his gun several times. No one was injured.

A motive wasn't immediately clear, but the Colorado State Patrol said the shooting didn't appear to be related to previous threats to the justices, all of whom were appointed by Democratic governors.

Dozens of lawsuits citing the constitutional provision were filed against Trump last year in a bid to end his presidential campaign, contending he disqualified himself by inciting the Jan. 6, 2021, attack on the U.S. Capitol to stop Democrat Joe Biden from replacing him as president.

None of the lawsuits succeeded until the Colorado court's ruling last month. Activists similarly asked dozens of top election officials to not place Trump on the ballot due to his alleged violation of Section 3. None acted until Maine's Shenna Bellows barred him a week after the Colorado ruling.

If the Supreme Court does not rule on the merits of the cases, legal experts say, states could face the legal chaos that the high court is supposed to dispel.

Advocates of disqualifying Trump argue the matter is simple — Section 3 makes him no longer eligible for the presidency, just as if he somehow didn't meet other constitutional requirements, such as being a natural-born citizen at least 35 years old.

Trump's attorneys contend that's a wild misreading of a vague clause that was rarely used after the 1870s. They contend that Jan. 6 was not legally an insurrection, that the provision doesn't apply to the president, and that whether Trump qualifies for the ballot is not a decision for unelected state judges to make.