(CNN) Michigan Rep. Justin Amash said on Wednesday that President Donald Trump's threat to hold up legislation until Democrats drop their investigations into him is "irresponsible."

"I think that's irresponsible, but what do you expect?" Amash told CNN after Trump's Rose Garden appearance denouncing Democrats' ongoing debate over impeachment.

Amash over the weekend became the first, and so far only, Republican to publicly describe Trump's conduct as impeachable , citing special counsel Robert Mueller's report.

He has largely flown under the radar since then, avoiding television appearances even as his comments made the question of impeachment more urgent for House Democrats.

"My job is to defend the Constitution. I'm laying out the information I want to lay out and it's not about getting on TV or anything like that," he told CNN on Wednesday afternoon. "I want to make sure that I'm presenting it in the most clear-cut, sober way possible."