Opinion | The Trump trial's Michael Cohen problem

Michael Cohen, former President Donald Trump’s lawyer and alleged fixer, should wear a warning label when he takes the witness chair in New York’s criminal hush money trial. Handle with care.

Following Stormy Daniels’ at times intense testimony, Cohen is scheduled to testify Monday. He will likely be the prosecution’s final major witness against Trump, who is facing 34 felony counts for creating false business records to conceal a campaign finance crime.

But is Cohen a star-crossed star witness?

A self-acknowledged liar, perjurer and convicted felon, prosecutors need to convince all 12 jurors that Cohen is telling the truth this time. If not, the prosecution’s case could fail.

No doubt, Cohen will testify that Trump participated in a criminal conspiracy to pay $130,000 in hush money to adult film star Daniels immediately before the 2016 election and to hide the true nature of the payment using false business entries. (Trump has pleaded not guilty and denied any wrongdoing.)

To prove Trump’s personal role in that conspiracy, prosecutors assuredly need the firsthand testimony of Cohen, a former Trump loyalist turned state’s witness. After all, who better to testify about a criminal plot than one of the plotters?

But Cohen’s damaging baggage is staggering. In 2018, Cohen pleaded guilty in federal court to tax evasion, making false statements to a bank, and illegal campaign contributions. In the Department of Justice’s press release, then-Deputy U.S. Attorney Robert Khuzami stated that Cohen “chose to break the law, repeatedly over many years and in a variety of ways.”

Following his guilty plea, Cohen was sentenced to three years of confinement, partly served in prison and partly under house arrest.

This year, Cohen unsuccessfully moved for early release from court supervision. Federal Judge Jesse M. Furman denied the motion and implied that Cohen had committed perjury previously. “At a minimum, Cohen’s ongoing and escalating efforts to walk away from his prior acceptance of responsibility for his crimes are manifest evidence of the ongoing need for specific deterrence,” Furman wrote.

Judge Arthur Engoron, who presided over the New York attorney general’s successful civil fraud trial against Trump and the Trump Organization, similarly acknowledged that Cohen’s credibility as a witness “was significantly compromised by his having pleaded guilty to perjury.” But Engoron, who decided that fraud case without a jury, stated in his ruling, “This factfinder does not believe that pleading guilty to perjury means that you can never tell the truth.”

Not surprisingly, Trump’s allies in Congress are also working to discredit Cohen. Last week the Republican-controlled House Judiciary Committee sent a referral to the Justice Department alleging that Cohen had lied to Congress six times, although such a move is mostly just symbolic.

All of this to say, Trump’s lawyers will have plenty of ammunition with which to impugn Cohen’s credibility. Indeed, the fierce and strident tactics used against Daniels last week may end up feeling like just a warmup compared to Cohen’s cross.

Aside from his criminal conviction and acknowledgments of prior perjury, Cohen has also publicly attacked Trump in his books, in interviews and on social media. On Friday, Trump’s attorneys specifically called out a recent TikTok of Cohen’s, prompting hush money Judge Juan Merchan to direct “the people to communicate to Cohen that the judge is asking him to refrain from making any statements about the case or Mr. Trump.”

His disdain for Trump is palpable.

Given this very public record, Trump’s defense counsel will no doubt try to depict Cohen as vindictive, duplicitous and angry that Trump did not give Cohen a job in his administration.

But the prosecutors know all this — and should have strategies to try to head off the defense. The cardinal rule for prosecutors questioning a convicted criminal in their case is to lay out every flaw, every defect and every credibility issue. Leave nothing undisclosed. Leave nothing hidden.

While that may seem counterintuitive, the logic is sound. While telling the jury about Cohen’s past legal baggage, the prosecutor assuredly will ask Cohen if he is testifying truthfully now and, if so, why. This neutralizes the venom before the defense lawyers ask their first question.

If credibility issues or past criminal acts are disclosed for the first time on the defense’s cross-examination, jurors understandably might worry what other damaging information has been withheld in Cohen’s direct testimony.

One nagging problem persists. The prosecutors only know what Cohen has told them and what they have independently discovered about Cohen’s past behavior. Cohen joined Trump’s organization in 2007 and by 2012 was described as Trump’s “pit bull.” Trump, and therefore Trump’s lawyers, could know much more about Cohen and his past actions than the prosecutors do.

However, Trump’s counsel needs to be cautious, too. Questioning Cohen about other alleged illegal or unethical actions that Cohen may have taken at Trump’s bidding could backfire against their client.

Demeanor matters as well. Juries are unpredictable. Combative cross-examination, with sharp and pointed exchanges between witnesses and defense counsel, can be powerful in persuading a jury or, alternatively, can be off-putting and repetitive.

Prosecutors will be counting on the Trump business records to corroborate Cohen’s account. Nonetheless, how Cohen holds up under defense counsel’s withering cross-examination will matter when the jurors deliberate in secret and decide whom to believe.

This article was originally published on MSNBC.com