Rep. Justin Amash Justin AmashInternal Democratic poll shows tight race in contest to replace Amash Centrist Democrats 'strongly considering' discharge petition on GOP PPP bill On The Trail: How Nancy Pelosi could improbably become president MORE (R-Mich) declined to return fire on Monday when a reporter asked his thoughts on President Trump Donald John TrumpBiden on Trump's refusal to commit to peaceful transfer of power: 'What country are we in?' Romney: 'Unthinkable and unacceptable' to not commit to peaceful transition of power Two Louisville police officers shot amid Breonna Taylor grand jury protests MORE calling him a "loser," saying simply: "OK."

The conservative lawmaker's comment comes as part of an ongoing back-and-forth with the president, which started over the weekend when Amash tweeted why he believes Trump committed "impeachable offenses."

Amash's comments made him the first congressional Republican to call for impeachment, and he went farther than many Democrats. He made those comments after reading special counsel Robert Mueller's 448-page report.

ADVERTISEMENT

"Mueller’s report reveals that President Trump engaged in specific actions and a pattern of behavior that meet the threshold for impeachment," he tweeted.

In response, Trump tweeted that Amash was a "loser" and a "total lightweight."

"How do you Obstruct when there is no crime and, in fact, the crimes were committed by the other side?" Trump tweeted Sunday. "Justin is a loser who sadly plays right into our opponents hands!"

On Monday, Amash doubled down on his comments, prompting Trump to again take a stab at the congressman.

Following the tweets, a pro-Trump Michigan state lawmaker said Monday that he would challenge Amash in the Republican primary for his House seat.

Speaking to reporters on Monday, Amash downplayed the challenge, saying, “It’s not serious."

He also responded to a question as to whether he felt safe in his seat for two more years: “I feel very confident in my district."

Amash's battle with Trump sparked backlash from the conservative House Freedom Caucus, of which he is a founding member. The body voted Monday night to condemn Amash's call for impeachment.