George Washington University professor Jonathan Turley testified at the House Judiciary Committee on Wednesday that impeaching President Donald Trump would violate the principles of the Constitution and set a bad precedent.

In contrast to the three Democrat witnesses — Harvard Law School professor Noah Feldman, Stanford Law School professor Pamela Karlan, and University of North Carolina Law School professor Michael Gerhardt, all of whom gave their opinions of Trump’s guilt — Turley, the sole Republican witness, said the Framers of the Constitution designed impeachment to avoid loose standards of criminality, and rejected “maladministration” as a cause.

He noted that he was not a supporter of President Trump, not had he voted for him, but was concerned that the Democrats were establishing a weak standard for impeachment in a partisan process that boded ill for the future:

This would be the first impeachment in history where there would be considerable debate — and, in my view, not compelling evidence — of the commission of a crime.

We are living in the very period described by Alexander Hamilton, a period of agitated passions. I get it. You’re mad. The president’s mad. My Republican friends are mad. My Democratic friends are mad. My wife is mad. My kids are mad. Even my dog seems mad. And Luna’s a golden doodle, and they don’t get mad.

So we’re all mad. Where has that taken us? Will a slipshod impeachment make us less mad? Will it only invite an invitation for the madness to follow every future administration?

That is why this is wrong. It’s not wrong because President Trump is right. His call is anything but perfect. It’s not wrong because the House has no legitimate reason to investigate the Ukrainian controversy. It’s not wrong because we’re in an election year. There is no good time for an impeachment.

No — it’s wrong because this is not how you impeach an American president.

Turley said that the Trump impeachment closely paralleled the 1868 impeachment of President Andrew Johnson, widely viewed as a partisan abuse of power. “It is not a model or an association that this committee should relish.”