A common refrain among pro-Trump conservative pundits as of late has been to compare Donald Trump and his inner circle to Al Capone, the notoriously violent mob boss “railroaded” by a tax-evasion conviction.

The latest culprit of this bizzare comparison was Harvard Law professor and Trump defender Alan Dershowitz who, appearing Monday morning on Fox & Friends, said, “The biggest crime you can commit in America today is to have been associated with Donald Trump. If you’re associated with Donald Trump, they’re going to Manafort you, they’re going to Cohen you. They’re going to do all of these things to you.”

He continued, dropping in a mob comparison: “They usually do it with the mafia. It’s the Al Capone approach. If we can’t get him on the grounds that we’d really want him on, let’s go after him on taxes, let’s go after him on business.”

“It’s targeting people,” he lamented, at one point using the phrase “legal colonoscopy” to describe how such actions might discourage businessmen from entering politics. “And if they can target President Trump, they can target you, they can target anyone. That’s the problem.”

Last week, Trump’s former personal lawyer Michael Cohen pleaded guilty to eight felony charges, including campaign-finance violations and other crimes which he claims were committed at the direction of then-candidate Trump.

Minutes later, Trump’s former campaign chair Paul Manafort was convicted on eight felony charges, including tax charges for failing to disclose millions of dollars he made lobbying for Ukrainian politicians.

He was also convicted of two counts of bank fraud—the same crime that landed Al Capone in prison for 17 years.

What’s especially striking about Dershowitz comparing the president of the United States to a murderous mob boss is that this isn’t even the first time a Trump supporter has publically made such a leap.

Last week, NRA spokesperson Dana Loesch turned Capone into a verb to argue Trump is the victim of unfair prosecution.

“They’re trying to Al Capone the president,” she said on her NRATV show. “I mean, you remember. Capone didn’t go down for murder. Elliot Ness didn’t put him in for murder. He went in for tax fraud. Prosecutors didn’t care how he went down as long as he went down. The same goes for Democrats. Whatever avenue is needed to bring down the president, they’ll take it.”

Earlier this month, conservative radio host Mark Levin reported that Special Counsel Robert Mueller’s impaneling of a grand jury for the Russia investigation is essentially a “coup” against the president. Conservative blog Right Wing News picked up Levin‘s comments, adding, “They are looking to catch these people in a process crime... Think Al Capone and the IRS. It’s a trap meant to take down the Trump Presidency.”

The conservative logic is clear: Trump is being slowly railroaded by various legal investigations—just like Al Capone.

What the president’s defenders seem to forget, however, is while Al Capone was eventually convicted of tax fraud, he was a notorious gangster and alleged murderer. Federal agents could never convict Capone on the violent crimes, eventually settling on tax-fraud charges to get him in prison.

So the metaphor of prosecuting like Al Capone means going after a guilty person for something else more provable in court—not for their most heinous offense. In a sense, these Trump defenders are unwittingly suggesting the president is guilty of far greater crimes.

Experts say that ignoring the mobster’s violent persona not only discredits this unusual conservative talking point, but is also harmful to Trump.

“What makes no sense is comparing the president to a convicted gangster. Al Capone is one of the most ludicrous, mystifying, unhelpful comparisons in politics,” Scott Talan, a professor at American University specializing in political communications, told The Daily Beast. “There is no comparison to this comparison, that’s how crazy it is.”

And yet the comparison seems to have originated from the president himself.

In a July interview following his private meeting with Russian President Vladimir Putin, Trump went to Sean Hannity’s Fox News show and defended Paul Manafort. “With Paul Manafort, who really is a nice man, you look at what’s going on with him, it’s like Al Capone,” Trump said.

A month later, the president did it again.

“Looking back on history, who was treated worse, Alfonse Capone, legendary mob boss, killer and ‘Public Enemy Number One,’ or Paul Manafort, political operative & Reagan/Dole darling, now serving solitary confinement - although convicted of nothing ?, ” Trump tweeted.

It remains unclear why Trump and his boosters continue to use this clearly flawed comparison of the president or anyone close to him with one of the most notorious figures in American history—one who usually receives little sympathy.

Talan believes the comparison is actually not about legality at all, but about personality.

“Maybe it’s because Donald Trump himself exhibits gangster-like qualities on Twitter and his past business deals,” he said. “Let’s face it: Donald Trump is a verbal gangster.”