What happens after historic Supreme Court ruling that states can't ban Trump from ballot

The U.S. Supreme Court on Monday essentially rendered moot a string of ongoing state-level challenges to former President Donald Trump's 2024 candidacy under Section 3 of the 14th Amendment of the Constitution, also known as the "insurrection clause."

Both Colorado's Supreme Court and Maine's top election official had determined Trump should not be on the Republican presidential primary ballot under Section 3 because of his conduct in the wake of his 2020 election loss and related to Jan. 6.

But the new U.S. Supreme Court opinion found that the state officials had no such authority to make that determination based on the 14th Amendment.

While the justices were specifically ruling on the Colorado decision, which Trump appealed in January, their rationale should end the ongoing legal dispute nationwide.

That paves the way for Trump to remain on every state's ballot on his path to likely winning another GOP presidential nomination and appearing in November's general election.

"Responsibility for enforcing Section 3 against federal officeholders and candidates rests with Congress and not the States," the court's majority opinion states. (Congress took up the question of Trump and insurrection when the House impeached him for alleged incitement in the wake of the Jan. 6 attack on the U.S. Capitol, though Senate Republicans acquitted him and he maintained he was innocent.)

Trump's candidacy has been questioned or reviewed in states including California, Illinois, Virginia and more -- with contradictory results.

Dozens of similar challenges have been considered by lower courts, election boards or secretaries of state over the past year and nearly all of them have been dismissed for reasons ranging from procedural inconsistencies, questions about whether the judicial branch had power to enforce the "insurrection clause" to disputes about the precise meaning of words in the text.

Last week, Illinois became the third state after Colorado and Maine in which an official determined Trump was ineligible for the 2024 primary ballot under Section 3. However, the judge stayed her decision pending appeal and noted that it would remain on pause if the U.S. Supreme Court issued a conflicting decision.

The U.S. Supreme Court's three liberal-leaning justices -- Sonia Sotomayor, Elena Kagan and Ketanji Brown Jackson -- in a concurring opinion on Monday said while they agreed the Colorado decision couldn't stand, they were at odds with the court's majority over their determination that only Congress can enforce Section 3.

Allowing Colorado to keep Trump off the ballot, they agreed, would "create a chaotic state-by-state patchwork, at odds with our Nation's federalism principles. That is enough to resolve this case."

Colorado and Maine are both Super Tuesday states, set to cast ballots and release their primary results on Tuesday.

The former president remained on both states' primary ballots ahead of Election Day.

Colorado and Maine's Secretary of State offices had both said they wouldn't reprint ballots if the U.S. Supreme Court were to find Trump ineligible -- they would simply not count votes for the former president.

More than 857,584 combined ballots have already been cast in both states' primaries.

Trump, who denies all wrongdoing, quickly celebrated the U.S. Supreme Court decision on Monday as a "BIG WIN FOR AMERICA!!!" while opponents to his qualification said they disagreed with the justices' view.

"Colorado should be able to bar oath-breaking insurrection[ists] from our ballot," the state's Secretary of State Jena Griswold, a Democrat, said in a statement.

However, she acknowledged, "In accordance with this decision, Donald Trump is an eligible candidate on Colorado’s 2024 Presidential Primary."

Separately, Maine Secretary of State Shenna Bellows, also a Democrat, modified her decision on Trump's ballot eligibility in the wake of the U.S. Supreme Court decision.

ABC News' Devin Dwyer contributed to this report.