The August decision by the 10th U.S. Circuit Court of Appeals in Denver puts "our country at risk," Secretary of State Jena Griswold said at a news conference attended by Attorney General Phil Weiser.
Griswold has decried the ruling as a violation of the one person, one vote principle. Weiser said the decision threatens to put presidential elections "in the hands of a few unaccountable presidential electors."
Four of the nine high court justices must agree to accept a case for it to be heard. Griswold and Weiser announced they'd filed their petition Wednesday, The Colorado Sun reported. Presidential electors almost always vote for the popular vote winner, and some states have laws requiring them to do so.
Under the Electoral College system, voters who cast a ballot for president are choosing electors who are pledged to that presidential candidate. The electors then choose the president at the Electoral College.
Colorado's political parties nominate the state's nine electors. In a split decision, the three-judge federal appeals panel said the Constitution allows electors to cast votes at their own discretion.
The panel ruled in the case of Colorado elector Micheal Baca, who refused to vote for Democrat Hillary Clinton, the presidential winner in Colorado in 2016. Baca crossed out Clinton's name on his ballot and wrote in John Kasich, the Republican governor of Ohio, who also ran for president.
Following state law, then-Secretary of State Wayne Williams removed Baca as an elector and replaced him with another who voted for Clinton. The 10th U.S. Circuit blocked a bid by two other Colorado electors to cast their ballots that year for someone other than Clinton. Those bids were blocked before the three-judge panel issued its decision in the Baca case.
Baca said in a written statement that he looked forward to having the Supreme Court "resolve the issue of elector freedom before the 2020 election." Jason Harrow, chief counsel with the nonprofit group Equal Citizens who represents Baca, said he welcomed the chance for a full hearing before the high court.
Equal Citizens also has asked the Supreme Court to take up a Washington case in which three electors were fined for refusing to vote for Clinton, the popular vote winner there. They cast their ballots for Republican Colin Powell.
The Denver appeals court ruling in the Baca case applies to Colorado and five other states in the 10th Circuit: Kansas, New Mexico, Oklahoma, Utah and Wyoming.
This story has been corrected to show Baca's first name is spelled Micheal.
Information from: The Colorado Sun, http://coloradosun.com