Today, in a 13-tweet thread, Michigan congressman Justin Amash chided his fellow Republicans for failing to respond appropriately to special counsel Robert Mueller’s report on Russian meddling in the 2016 US presidential election and Donald Trump’s efforts to thwart the investigation. Amash is calling for Trump’s impeachment.

He believes his colleagues are failing the US Constitution and the American people. He says Republicans are deliberately shirking their duty to thoroughly review Mueller’s 11 conclusions on obstruction of justice by the president. The report doesn’t clear Trump, Amash argues, but his colleagues are avoiding reading it closely because if they do they’ll be compelled to conclude as he did after a thorough consideration of the findings that Trump committed an impeachable offense. His first tweet outlines his position.

In the following tweet, Amash writes, “I offer these conclusions only after having read Mueller’s redacted report carefully and completely, having read or watched pertinent statements and testimony, and having discussed this matter with my staff, who thoroughly reviewed materials and provided me with further analysis.”

The Michigan representative accused Attorney General William Barr of “misrepresentations that are significant but often subtle.” He believes Barr intended to deceive the public about the gravity of Mueller’s conclusions in an act of blatant partisanship.

There is much debate over what precisely qualifies under the elusive term “impeachable offense,” but the congressman has no question that Trump’s behavior fits and that Barr knew that when he minimized Mueller’s findings upon publication. Amash writes:

Under our Constitution, the president “shall be removed from Office on Impeachment for, and Conviction of, Treason, Bribery, or other high Crimes and Misdemeanors.” While “high Crimes and Misdemeanors” is not defined, the context implies conduct that violates the public trust.

Amash points out that the burden of proof required for impeachment is lower than that required to charge someone with a criminal offense. In light of this, the lawyer didn’t hesitate to call for impeachment, writing, “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.” He notes that “Mueller’s report identifies multiple examples of conduct satisfying all the elements of obstruction of justice.” Amash believes that “undoubtedly any person who is not the president of the United States would be indicted based on such evidence.”

Whether he is a persuasive enough attorney to convince his fellow Republicans of this is unclear as yet. Based on the Republican record thus far, however, Amash is on his own. He appears to be the first sitting Republican representative to call for Trump’s impeachment.

Readers of his thread expressed immediate appreciation of his willingness to cross party lines. They thanked Amash for this rare distinction and what they called his principled stance, his “bravery,” and his “commitment to the Constitution.”