DENVER (AP) — Colorado’s endangered Republican senator Cory Gardner may be a casualty of the party’s push to seat a new Supreme Court justice before the election.

Gardner already had a steep uphill path to reelection in increasingly Democratic Colorado. He faces John Hickenlooper, a popular former governor and mayor of Denver who has been trying to portray himself as an independent-minded bipartisan politician.

Republicans acknowledge that Gardner’s vow to confirm President Donald Trump’s Supreme Court nominee ties him to the president and GOP at the worst possible time.