President Trump on Monday denied that hush-money payments to adult film star Stormy Daniels and Playboy model Karen McDougal in the weeks leading up to the 2016 election were campaign contributions, instead calling them a "simple private transaction.”

Michael Cohen, Trump’s former lawyer, admitted in a plea deal to violating federal campaign finance laws by arranging payments to Daniels and McDougal on Trump's behalf

On "Fox & Friends" Monday, constitutional law professor Jonathan Turley said the possible campaign finance violations are "very serious" crimes, but difficult to prove.

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"This is a very serious thing. The Department of Justice is building a classic case with immunity deals and these allegations against the president of the United States," Turley said.

He noted, however, that prosecutors must prove that there was intent to violate federal election laws, and there is a "readily available alternative narrative": a married man paying women to stay silent about potentially embarrassing affairs.

"These are difficult crimes to prosecute, as John Edwards showed," Turley said, referring to the former Democratic presidential candidate who was unsuccessfully prosecuted over a similar scandal in 2008.

"This is serious and this could get more serious. But there's no evidence that not confirming these payments before the election had any serious impact on the election," Turley said. "It doesn't make any of this good, but we don't need the hyperbole and the hype over this."

In a Fox News op-ed, former U.S. attorney Andy McCarthy said the president is "likely" to be indicted by New York federal prosecutors for the campaign finance violation. 

He wrote:

The major takeaway from the 40-page sentencing memorandum filed by federal prosecutors Friday for Michael Cohen, President Trump’s former personal attorney, is this: The president is very likely to be indicted on a charge of violating federal campaign finance laws.

It has been obvious for some time that President Trump is the principal subject of the investigation still being conducted by the U.S. attorney for the Southern District of New York.

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