Story highlights Coffman is from a competitive district

"Honestly, I don't care for him much," he said of Trump

(CNN) One Colorado Republican has taken his discomfort with his party's presidential nominee to the airwaves.

The ad, posted Thursday morning, opens with Rep. Mike Coffman speaking directly to the camera, saying: "People ask me, 'what do you think about (Donald) Trump?' Honestly, I don't care for him much."

He adds: "And I certainly don't trust Hillary (Clinton.)"

Coffman represents a bellwether district in the Denver area, and he's running against Democrat Morgan Carroll. The district is comprised of more moderate voters, suburban mothers and Hispanics -- all voting blocs Trump has struggled with. As he notes in the ad, the congressman is a Marine, and prior to that, he was also in the Army reserves.

This version of the ad, along with a Spanish-language one, appeared on YouTube midday Wednesday. The original version, which has since been made private , contained brief footage of Coffman in a congressional hearing and could have drawn an ethics complaint over a House rule violation were it to air on television.

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