The U.S. Supreme Court announced Friday it will consider a Colorado case that could have major ramifications for how the Electoral College selects the next American president.

The case dates to 2016, when three Democratic Electoral College electors — instructed by state law to vote for Hillary Clinton — instead tried to vote for Republican John Kasich to prevent Donald Trump from receiving the 270 votes required to become president.

Two of the Colorado electors backed down and voted for Clinton, but a third, Micheal Baca, did not. After he was replaced by then-Secretary of State Wayne Williams, the electors filed a lawsuit challenging his removal.

The 10th Circuit ruled in August that Baca could legally challenge his dismissal and that “the state’s removal of Mr. Baca and nullification of his vote were unconstitutional.”

“We are thrilled the Supreme Court will take up our cases, and we look forward to our historic day in court,” Baca and Bret Chiafalo, a faithless elector in Washington state, said in an emailed statement Friday. Their cases have been merged by the Supreme Court. “The states had no power to penalize us merely for exercising our right to vote.”

Colorado’s attorney general asked the U.S. Supreme Court to consider the case, noting that a state supreme court in Washington had reached a different conclusion about Chiafalo and so-called “faithless electors.” On Friday, the Supreme Court agreed to do so.

“Having the U.S. Supreme Court resolve this critical question about the foundation of our democracy before the 2020 election will avoid the uncertainty, chaos, and confusion that would arise in the wake of post-election litigation,” said Attorney General Phil Weiser, a Democrat.

Most states, Colorado included, have laws binding electors’ votes to the winner of the popular vote and some, such as Colorado, can punish faithless electors. A key question before the high court will be whether those laws are constitutional.

Weiser believes they are. Because the Constitution gives states the power to appoint electors, states also have the power to remove electors for not fulfilling their duties, he argues.

Lawyers for the electors disagree. They say the power to appoint electors does not imply a power to control them. They compare it to a governor’s power to appoint U.S. senators when there is a vacancy. There’s no corresponding power to remove them from office or control their votes.

The case — Colorado Department of State vs. Micheal Baca, et al. — will likely be heard in April and decided before the court’s term ends in late June.

“Unelected, unaccountable presidential electors shouldn’t be allowed to decide the presidential election without regard to voters’ choices and state law,” said Secretary of State Jena Griswold, a Democrat. “When Americans vote in the presidential election, we are exercising our most fundamental right — the right to self-governance.”

The faithless electors are backed by Lawrence Lessig, a Harvard Law professor and founder of Equal Citizens. In October, Lessig said he agreed with Weiser that the Supreme Court should consider the case “before this unsettled issue causes chaos in the 2020 election or one soon after.”

“We are glad the Supreme Court has recognized the paramount importance of clearly determining the rules of the road for presidential electors for the upcoming election and all future elections,” Lessig said Friday.

Earlier versions of this report gave an incorrect spelling for Micheal Baca’s name.