Controversial lawyer Alan Dershowitz on Tuesday said Michael Cohen's guilty plea for breaking campaign finance law may not be as big a problem for President Trump as his critics hope and his supporters fear.

“This is the beginning of a story that will unravel over time, but it's not nearly as deadly lethal as some have portrayed it as being," Dershowitz, a staunch defender of Trump's civil liberties amid special counsel Robert Mueller's federal Russia investigation, said during an interview on Fox News.

[Opinion: Cohen's plea could land Trump in the witness chair]

Dershowitz downplayed the significance of election law violations, claiming "every" administration and presidential candidate commits them.

“Here, they’re trying to elevate this into an impeachable offense or a felony against the president," he continued. "Naming someone as an un-indicted co-conspirator is very unfair because he has no opportunity to defend himself or herself. And yet that may happen."

Cohen pleaded guilty in a New York federal district court on Tuesday to five tax evasion charges for failing to report $4 million in income from 2012 to 2016 and one count of making a false statement to a lending institution from 2015 to 2016 when applying for a home equity line of credit. He also pleaded guilty to charges associated with willfully causing an unlawful corporate contribution in 2016 and one count of making an excessive campaign contribution in 2016.

The last charge is believed to be tied to nondisclosure agreements he brokered before the 2016 election for porn star Stormy Daniels and former Playboy model Karen McDougal, who both claim to have had extramarital affairs with Trump. He told the court Tuesday he had been directed to make the arrangements by an unnamed federal candidate in exchange for the women's silence.

Cohen's charges stemmed from an investigation spearheaded by the U.S. Attorney's Office in the Southern District of New York after it received a referral from Mueller's team.

Dershowitz, a self-described liberal Democrat who has gained notoriety for his criticism of Mueller's Russia probe, complained in July he had been "shunned" by former friends holidaying at Martha's Vineyard, Mass., over his pro-Trump posturing.