The Republican who endorsed impeachment just demolished his party's embarrassing defense of Trump

Republican Rep. Justin Amash came under fire over the weekend from his fellow party members when he  explicitly condemned President Donald Trump's actions described in Special Counsel Robert Mueller's report and said it showed he committed impeachable offenses by obstructing justice.

Amash is clearly undeterred by his GOP critics, which include the Republican National Committee Chair Ronna McDaniel and the president himself. In a new Twitter thread on Monday, the Michigan lawmaker debunked many of the mistaken and weak defense of Trump's actions. Many have criticized the idea that an obstruction of justice charge could possibly be warranted.

For example, Trump said on Twitter, "[H]ow do you Obstruct when there is no crime and, in fact, the crimes were committed by the other side?” (He added: “Justin is a loser who sadly plays right into our opponents hands!”[sic])

As Amash pointed out, the idea that "there is no crime" in the Russia case is just false.

"In fact, there were many crimes revealed by the investigation, some of which were charged, and some of which were not but are nonetheless described in Mueller’s report," he said.

Rudy Giuliani, the president's lawyer, has further argued it is "almost impossible to have obstruction of justice if there's no underlying crime." Attorney General Bill Barr has made a related, though different, claim that because Mueller was unable to find clear evidence of an underlying conspiracy with Russia, this suggests that Trump didn't have the corrupt intent required to obstruct justice.

But Amash likewise dispatched with this argument.

"In fact, obstruction of justice does not require the prosecution of an underlying crime, and there is a logical reason for that. Prosecutors might not charge a crime precisely *because* obstruction of justice denied them timely access to evidence that could lead to a prosecution," he wrote. (Indeed, I have argued that in at least one instance, one can reasonably suspect Trump may have obstructed Mueller from finding evidence of a conspiracy with Russia.)

Amash added: "If an underlying crime were required, then prosecutors could charge obstruction of justice only if it were unsuccessful in completely obstructing the investigation. This would make no sense."

Another argument, endorsed most forcefully and troublingly by Barr, is that Trump as president almost in principle couldn't be guilty of obstructing justice when he believed, sincerely, that the investigation was pointless because there was no underlying crime. This many brings up thorny constitutional issues about presidential powers, but Amash skillfully avoided dealing with these tricky questions.

"In fact, the president could not have known whether every single person Mueller investigated did or did not commit any crimes," he wrote. Mueller also argued in the report that even if Trump thought the investigation was spurious, he could still be guilty of corruptly obstructing it if he wanted to avoid personal embarrassment.

While he persuasively dismantled these defenses of Trump, Amash added another point even if his critics still aren't convinced Trump is guilty of a crime.

He noted that some of Trump's defenders (notably legal scholar Alan Dershowitz) "imply 'high Crimes and Misdemeanors' requires charges of a statutory crime or misdemeanor."

However, this isn't so — the basis for impeachment in the Constitution is left quite broad.

"In fact, 'high Crimes and Misdemeanors' is not defined in the Constitution and does not require corresponding statutory charges," Amash said. "The context implies conduct that violates the public trust—and that view is echoed by the Framers of the Constitution and early American scholars."