Rep. Justin Amash (R-MI) met with a group of students on Capitol Hill Tuesday and discussed why he believes impeachment proceedings against President Donald Trump should begin.

CBS News reporter Bo Erickson shared a photo of the gathering on social media, tweeting: “Wow: @justinamash is NOT backing down. He is now talking to a school group on steps of the Capitol about why Trump impeachment proceedings should begin. “Really dangerous for our country” when ppl don’t tell the truth.”

The specifics of Amash’s remarks to students remain unclear.

Amash on Saturday became the first member of President Trump’s party on Capitol Hill to accuse him of engaging in “impeachable conduct” stemming from special counsel Robert Mueller’s lengthy investigation into Russian meddling in the 2016 presidential election.

Often a lone GOP voice in Congress, Amash sent a series of tweets Saturday criticizing both President Trump and Attorney General William Barr over Mueller’s report. Mueller wrapped the investigation and submitted his report to Barr in late March. The special counsel found the president’s campaign did not collude with Russia, while Barr and Deputy Attorney General Rod Rosenstein determined President Trump did not obstruct justice.

Amash said he reached four conclusions after carefully reading the redacted version of Mueller’s report, including that “President Trump has engaged in impeachable conduct.”

“Contrary to Barr’s portrayal, Mueller’s report reveals that President Trump engaged in specific actions and a pattern of behavior that meet the threshold for impeachment,” the congressman tweeted. He said the report “identifies multiple examples of conduct satisfying all the elements of obstruction of justice, and undoubtedly any person who is not the president of the United States would be indicted based on such evidence.”

The backlash from Republicans was swift and sharp against the libertarian-leaning lawmaker.

“He’s been against Trump from the beginning,” President Trump told reporters on Monday. “Personally I think he’s not much.”

House Republican leader Kevin McCarthy (R-CA) on the Fox News Channel questioned whether Amash really belongs among GOP congressmen. “You’ve got to understand Justin Amash. He’s been in Congress quite some time,” McCarthy stated. “I think he’s asked one question in all the committees that he’s been in. He votes more with Nancy Pelosi than he ever votes with me. It’s a question whether he’s even in our Republican conference as a whole.”

However most notably, the fifth-term lawmaker drew a primary challenger for his Grand Rapids-area seat in the 2020 elections.

“Amash has consistently voted against President Donald Trump on important issues,” said Michigan State Rep. Jim Lower (R), who announced his campaign Monday after Amash’s tweets. Lower said, “Most Republican Party primary voters support the president and want a congressman that would work with him to get his agenda done.” He accused Amash of “standing in the way” and said the congressman has moved away from the party over several years.

The House Freedom Caucus on Monday evening voted to formally condemn Amash over his remarks.

House Oversight Committee ranking member Jim Jordan (R-OH), who once served as Freedom Caucus chair, said 30 members in attendance of the caucus’s weekly meeting voted to denounce the lawmaker. “It was every single person who totally disagrees with what he says,” Jordan told reporters, according to The Hill. “What concerns me is Justin was viewed as a leader, right, on protecting privacy rights first to First Amendment rights.”

 The Associated Press contributed to this report.