Rep. Justin Amash (R-Mich.) came out against President Trump and Attorney General Bill Barr's presentation of the Mueller report, saying Trump "has engaged in impeachable conduct," on Saturday afternoon.

The big picture: Amash is the first Republican congressman to speak out in favor of impeaching Trump.

Our thought bubble per Axios' David Nather: Amash has departed from the party line many times, and he’s unlikely to bring a lot of House Republicans with him. But don’t underestimate the significance of this coming from a Republican with a history of independence. Amash was the only Republican to sign onto a Democratic bill that would've stopped Trump from declaring a national emergency to pay for the border wall, reports the Washington Post.

What he is saying:

Amash also tweeted that Barr's "misrepresentations are significant but often subtle," and that special counsel Robert Mueller's report shows that Trump "engaged in specific actions and a pattern of behavior that meets the threshold for impeachment."

He also took aim at congressional members who didn't bother to read the report because "their minds were made up based on partisan affiliation."

Amash also blamed Republican partisanship from preventing the system of checks and balances to take effect.

Go deeper: Trump's new impeachment trap