Tancredo ran for governor in 2014, this time as a Republican, because of his opposition to Colorado governor John Hickenlooper's refusal to execute convicted murderer Nathan Dunlap, and because of Hickenlooper's attempts to pass gun control legislation. Tancredo competed for the Republican Party's nomination with Bob Beauprez, Steve House, Greg Brophy, Mike Kopp, and Scott Gessler. Tancredo lost the primary to Beauprez. He once again left the Republican Party in 2015, becoming an independent. Tancredo again ran as a Republican for governor in 2018, but withdrew from the race.