Sen. Mark Kelly (D-Ariz.) vowed he’s “not backing down” in the face of threats from President Donald Trump.

Kelly, a former U.S. Navy fighter pilot and astronaut, drew Trump’s fury after he and several other Democrats released a video urging U.S. troops to refuse unlawful orders. Trump accused the lawmakers of sedition “punishable by death” in a social media post. The Pentagon has since said it is investigating Kelly for possible breaches of military law related to the video.

On Tuesday’s “Jimmy Kimmel Live!,” Kelly responded defiantly.

The senator blasted Defense Secretary Pete Hegseth as “totally unqualified” for his job, saying his only role was to please the president.

He also pointed out an absurdity.

It’s “kind of wild,” said Kelly, “because we recited something in the Uniform Code of Military Justice and he’s going to prosecute me under the Uniform Code of Military Justice for reciting the Uniform Code of Military Justice.”

“It is so ridiculous. It’s almost like you can’t make this shit up,” he added.

Watch the full interview here: