It’s the criminal trial of Donald J. Trump. And yet, a spectator who attended proceedings this week could have been forgiven some confusion.
It is not the former president who has come in for sustained criticism from witnesses. It is his former fixer, Michael D. Cohen, who paid the hush money at the heart of the case.
The prosecution’s witnesses have called Mr. Cohen — expected to testify himself before the trial ends — a “jerk,” “sort of a pants-on-fire type of guy,” and someone reminiscent of a jumpy animated dog from the children’s movie “Up.”
“He was a challenging client,” Mr. Cohen’s former banker said. “I didn’t particularly like dealing with him,” a lawyer testified.
It might seem strange that prosecutors from the Manhattan district attorney’s office are eliciting such testimony about their central witness, especially given that the defense has already begun attacking Mr. Cohen’s credibility.
But prosecutors often have to put a cooperating witness’s past behavior into a context that doesn’t undermine their case. They refer to it as inoculating the jury or, sometimes, airing out the dirty laundry.
Mr. Cohen, who pleaded guilty to federal crimes in 2018, was often belligerent as he did Mr. Trump’s bidding. It appears that the district attorney’s office will seek to turn that to their advantage: So far, they’ve drawn smiles and chuckles from jurors when asking witnesses to discuss Mr. Cohen.
“I didn’t want to receive a million frustrating phone calls from Michael,” said the lawyer, Keith Davidson, who in 2016 represented a porn star, Stormy Daniels, who received the hush money. “He created this drama and this situation.”
According to the Manhattan district attorney’s office, the situation was this: Mr. Cohen worked on behalf of his boss, then a presidential candidate, to stop Ms. Daniels from publicizing her story about having had sex with Mr. Trump in 2006. Prosecutors have accused the former president of falsifying business records to cover up the hush money deal and charged him with 34 felonies.
A lead prosecutor, Joshua Steinglass, who is an experienced trial lawyer, has at times seemed to embrace witnesses’ swipes at Mr. Cohen. On Tuesday, he asked Mr. Davidson about a text message he had received from Ms. Daniels’s manager in 2016 asking that he “call that jerk back.”
Mr. Steinglass could have let the moment slide, but instead he said: “I hate to ask it this way, but who was that jerk?”
“It was Michael Cohen,” replied Mr. Davidson. Several jurors smiled.
Prosecutors on Tuesday also made sure to enter into evidence the voice of one person who strongly approved of Mr. Cohen. “Michael Cohen is a very talented lawyer,” Mr. Trump said, in a recording from a news conference in 2017 that was played in the courtroom. “He’s a good lawyer at my firm.”
The video suggests that prosecutors will argue, as Mr. Cohen himself has, that his aggressive behavior was in service of his former boss. Mr. Cohen is not accused of any wrongdoing by state prosecutors and has cooperated with their investigation for years.
Prosecutors have asked Mr. Davidson and other witnesses to confirm text messages and emails with Mr. Cohen in which they arranged hush-money deals with women claiming sexual impropriety by Mr. Trump.
And David Pecker, the former publisher of The National Enquirer, has already corroborated many facts about which Mr. Cohen is expected to testify.
Still, there are openings for the defense to push its case against Mr. Cohen’s credibility. That effort began in earnest during their opening statements, where Mr. Trump’s lead lawyer, Todd Blanche, called the former fixer a “criminal,” a “liar” and a person obsessed with “getting Trump.”
The prosecution’s witnesses have also given Mr. Trump’s team ammunition for when they eventually cross-examine Mr. Cohen. Some have said things that the defense may seize on in an effort to show that Mr. Cohen acted to please his boss, but without his knowledge.
“He wasn’t part of the campaign, but I think he may have heard things informally, or he injected himself into it,” Mr. Pecker said at one point.
And Mr. Davidson said that Mr. Cohen, while discussing the hush-money payment to Ms. Daniels, said, “I’ll just do it myself.”
But Mr. Davidson offered other testimony that might make it hard to argue Mr. Cohen operated independently.
When asked why Mr. Cohen kept delaying the payment, Mr. Davidson said: “Michael Cohen didn’t have the authority to actually spend money.”
That’s why, he said, he had always expected the money to come from someone else: Mr. Trump.