On August 31, the Colorado Republican Party filed this amicus curiae brief in the Tenth Circuit in Baca v Williams, 18-1173. This is the case over whether presidential electors have a right to vote for anyone who meets the constitutional qualifications to be president, or whether states can force them to vote for the presidential candidate who received the most popular votes in that state.
The lawsuit had been filed in 2016 by several Democratic presidential electors, so it is somewhat odd that the Republican Party is intervening. The Republican Party supports the position of the state of Colorado. The state believes that any presidential candidate who votes for someone other than the popular vote winner thereby ceases to be an elector, even though the voters in November chose the electors.