Here is why Donald Trump may lose big if a judge rules on executive privilege
President Donald Trump and Rudy Giuliani

One of Robert Mueller's top deputies laid out a provocative legal theory about why President Donald Trump may not want to litigate the issue of executive privilege.

Andrew Weissmann, the former chief of the criminal fraud section of the Department of Justice, explained to MSNBC's Nicolle Wallace on Tuesday the theory behind a new piece he wrote for Just Security with Ryan Goodman.

"What both sides ignore is a reason that the White House might never truly want to litigate the executive privilege question. That’s because it could cause a federal court (or the Chief Justice) in short order to make the determination that the President committed a crime," they wrote. "Those advising the President would be wise to think hard before taking the actual step of asserting executive privilege to block the testimony of John Bolton or others."

The two explained the "crime-fraud" exception to privilege.

"Indeed, the Chief Judge in the District of Columbia courthouse, where the White House would need to bring a court case to block testimony based on a claim of executive privilege, has dealt with the crime fraud exception to the attorney-client privilege (which is generally more absolute than the executive privilege). Judges even warn counsel away from contesting the issue in these kinds of situations by noting that the court would then be compelled to determine if the relevant communications involved criminal activity," they wrote.

"Paul Manafort’s counsel knows this lesson well, where the court issued a lengthy decision finding that his communications with his legal counsel in 2016-17 concerning FARA fell within the crime fraud exception. Notably, as the court held, it is not necessary for both parties — the client and lawyer — to be involved in the fraud; it is sufficient that the client was seeking to perpetrate (sic) the fraud. The same should apply to the analysis of a claim of executive privilege," they reminded.

Former acting solicitor general Neal Katyal says the reasoning would be the same if the issue were decided in the Senate impeachment trial by Chief Justice John Roberts.