Former President Donald Trump did himself no favors in his appearance in court for the E. Jean Carroll trial, argued former federal prosecutor Joyce Vance on Thursday's edition of MSNBC's "The Beat."

Carroll, an advice columnist, alleges Trump sexually assaulted her in a Manhattan department store in the 1990s. A jury already found Trump liable for sexual abuse and defamation, and the current trial is purely about assessing additional damages. Trump has responded to his legal troubles by continuing to attack Carroll on social media.

During today's proceedings, Trump personally gave testimony, only to run into a buzzsaw as Judge Lewis Kaplan put him in his place.

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"As I mentioned, some of the underlying incident and stakes are higher than what happened today, although most presidential candidates aren't in a courtroom in the first place, regarding such serious matters," said anchor Ari Melber, himself an attorney. "Your thoughts on what is important here and the failed attempt by Trump's lawyer to kind of season or add to what was supposed to be a very narrow purpose, proceeding under the judge's orders?"

"Yeah, I mean, this was fascinating," said Vance. "The former president taking the witness stand and testifying. There had been a lot of speculation, what he or wouldn't he? At the end, it was clear that Donald Trump took the witness stand because Donald Trump wanted to testify. I think the more experienced lawyer with a better client control would've talked him out of doing it and ultimately, he scored no points with the jury."

In fact, she added, "If anything, some of his best behavior in the courtroom may be something that they hold against him."

Watch the video below or at the link here.

Joyce Vance says Trump's courtroom performance may have hurt him with the jurywww.youtube.com