DENVER — A U.S. appeals court in Denver said Electoral College members can vote for the presidential candidate of their choice and aren’t bound by the popular vote in their states.

The 10th U.S. Circuit Court of Appeals ruled Tuesday that the Colorado secretary of state violated the Constitution in 2016 when he removed an elector and nullified his vote when the elector refused to cast his ballot for Democrat Hillary Clinton, who won the popular vote.

It was not immediately clear what effect the ruling might have on the Electoral College system, which is established in the Constitution. Voters in each state choose members of the Electoral College, called electors, who are pledged to a presidential candidate. The electors then choose the president.

Most states require electors to vote for the candidate who won the popular vote in that state, but the Denver appeals court said the states do not have that authority.

The Constitution allows electors to cast their votes at their own discretion, the ruling said, “and the state does not possess countervailing authority to remove an elector and to cancel his vote in response to the exercise of that Constitutional right.”

The elector at the center of the case, Micheal Baca, was part of a group known as “Hamilton electors” who tried to convince electors who were pledged to Clinton or Donald Trump to unite behind a consensus candidate to deny Trump the presidency.

After a flurry of filings in state and federal courts, the electors met on Dec. 19, 2016, and Baca crossed out Clinton’s name on his ballot and wrote in John Kasich, the Republican governor of Ohio who also ran for president.

Then-Secretary of State Wayne Williams refused to count the vote and removed Baca as an elector. He replaced him with another elector who voted for Clinton.

Baca’s attorneys said the U.S. Supreme Court will likely hear the case because it conflicts with a decision from Washington state’s Supreme Court. That court said in May that electors could be fined for not casting ballots for the popular vote winner.

Colorado’s current secretary of state, Jena Griswold, decried the ruling Tuesday in Colorado but did not immediately say if she would appeal.

“This court decision takes power from Colorado voters and sets a dangerous precedent,” she said. “Our nation stands on the principle of one person, one vote.”