In a move that grabbed national attention, Rep. Mike Coffman (R-Colorado) released a TV ad featuring his promise to “stand up to” Donald Trump of the GOP nominee becomes president.

“I don’t care for him much,” Coffman declares on-camera in the ad, which might lead a viewer to conclude that Coffman has decided to take a firm stance against Trump in the presidential race.

We followed up with Coffman on Thursday and found that’s not precisely the case. Instead, Coffman is walking a fine line and saying that he's undecided in the presidential race.

While the ad is intended to showcase a stance against the leader of his party, Coffman stopped short of disavowing Trump’s candidacy in a telephone interview with 9NEWS.

9NEWS: "Would you rule out supporting Donald Trump for president?"

Coffman also said that he currently has no candidate he backs in the Presidential race and that he’s considering a vote for Libertarian party nominee Gary Johnson in November.

“It’s an option,” Coffman said of Johnson. “I wouldn’t rule it out.”

Coffman said he draws a distinction between a possible vote for Trump and a formal endorsement of his party’s candidate—but that he might not give Trump either.

“It’s hard for me to see at this point in time that Trump could change to the extent that I would lend my name to his campaign,” Coffman added. “If [Trump] continues down the path that he continues, I’m not going to support him, I don’t think there’s a question about that.”

Coffman is defending his seat from a challenge by Democratic state lawmaker Morgan Carroll, who has endorsed Hillary Clinton for president.

EDITOR'S NOTE: An earlier version of this story misidentified Morgan Carroll as a former state lawmaker, not a current one.