Former President Donald Trump was impeached by the House of Representatives in his last week in office after his constant lies about the 2020 election prompted a mob of pro-Trump extremists to storm the United States Capitol in a deadly failed insurrection.

On Tuesday, Senators heard arguments from the House impeachment managers and Trump's defense team on whether the deliberative body has the authority to hold an impeachment trial for a President who is no longer in office.

Using founding documents and past precedent, Congressman Jamie Raskin (D-MD) argued in the affirmative, delivering an opening argument that was widely praised for its use of logic, coupled with a harrowing video breakdown of the deadly failed insurrection at the Capitol that spurred Trump's impeachment in the first place.

After Raskin and other House impeachment managers made their argument, Trump defense lawyer Bruce Castor addressed the Senate in a rambling 45 minute diatribe that was thin on any coherent case for why the Senate should refuse to hear the trial.

Even pro-Trump figures like former Trump lawyer Alan Dershowitz were left befuddled by the argument.

At one point, Castor admitted that his partner on Trump's defense team—David Schoen—was meant to deliver the first remarks, but that they switched the order after seeing the strength of the House impeachment managers' opening argument.

Watch below.

Castor said to the Senate and the millions watching the trial:

"I'll be quite frank with you, we changed what we were going to do on account that we thought the House managers' presentation was well done, and I wanted you to know that we have responses to those things."

The lawyer went on to express surprise that the House team began with a video detailing the Capitol riots and the gravity of Trump's transgressions, instead of focusing solely on the legitimacy of a Senate trial for a former president.

Soon after the day's arguments were over, reports trickled in that the former President was enraged at his defense team's ineptitude.

A report by Maggie Haberman of the New York Times further confirmed Trump's frustration, particularly his ire at the commendation Castor publicly gave to the Democratic House impeachment managers.

According to the report:

"That one of his own lawyers praised the prosecutors surprised and infuriated Mr. Trump, people familiar with his reaction said. And other Trump allies said privately that some members of the legal team seemed surprised by the raw clips from the riot that the Democrats showed, even though the House managers had signaled for days that was their plan."

Trump's unwillingness to concede praise (or elections) to his perceived enemies has been widely on display since even before Trump was President.

Whatever provoked Trump's anger, his critics were glad to hear of his diminished faith in his own defense team.

Castor's argument was widely mocked across the internet.

The next round of arguments begins on Wednesday at 12 pm Eastern time.