Washington (CNN) President Donald Trump on Monday sought to downplay the campaign-finance crimes of his former attorney Michael Cohen by returning to a theme he's sounded before: Comparing Cohen's actions to a civil violation of federal election law by President Barack Obama's first campaign.

Legal experts say there's no comparison between the two.

In a series of early morning tweets Monday, Trump asserted Cohen's payments to silence two women who claimed affairs with him amounted to a "simple private transaction" rather than illegal campaign contributions.

But even if the payments had been campaign contributions, he argued, they should result in a "CIVIL CASE like Obama's" and any blame should fall on Cohen, not him.

"Lawyer's liability, if he made a mistake, not me," Trump tweeted.

Richard Hasen, an election-law expert at the University of California at Irvine, said Cohen's action and the civil fine Obama paid over technical violations are "not in the same league."

"When you are dealing with a $1 billion operation, there are going to be some clerical mistakes," Hasen said of Obama's 2008 campaign.

"It's really an apples and oranges comparison," added Paul Ryan, the top lawyer at Common Cause, a watchdog group. Common Causes' January complaint with the Federal Election Commission prompted Cohen to publicly admit making a hush-money payment to porn star Stormy Daniels.

The payment, just days before the 2016 general election, was aimed at keeping her quiet about a decade-old tryst Daniels said she had with Trump.

"We are not talking about minor, technical violations," Ryan said of the allegations against Cohen.

"The Obama civil penalty was consistent with the types of fines that most big campaigns end up paying after an election for reporting errors," he added.

Fines for reporting errors and failing to quickly resolve excess contributions are not uncommon. Five years after his 1988 presidential campaign, an FEC audit triggered a $120,000 penalty for Republican Bob Dole's campaign.

Cohen, who is scheduled for sentencing Wednesday before a federal judge in New York, has admitted to serious felony violations of federal campaign-finance laws. He has acknowledged paying $130,000 to Daniels.

Cohen also has admitted helping orchestrate a $150,000 payment from the parent company of the National Enquirer, to bury news of an affair allegation from another woman, Playboy model Karen McDougal.

Last week, federal prosecutors linked Cohen's actions directly to the President for the first time, saying Trump directed Cohen to make the hush-money payments.

Trump has denied the affairs and has not been charged with any crimes.

Paperwork violation

In contrast to the case against Cohen, Obama's civil case centered on a series of technical and reporting violations uncovered in a 2012 audit by the Federal Election Commission. In the end, Obama's campaign agreed to pay a $375,000 fine in 2013 -- one of the largest penalties in agency history -- over the violations.

Among them: The Obama campaign missed filing deadlines for disclosing a slew of last-minute contributions and did not promptly refund $1.36 million in excess contributions

Federal law barred an individual from donating more than $2,700 to a presidential candidate in the 2016 primary or general election. Corporations, such as American Media, are prohibited from donating directly to federal candidates.

In a sentencing memo filed Friday, federal prosecutors in New York argued that Cohen willfully broke campaign-finance laws to influence the 2016 election.

"With respect to both payments," they wrote, "he acted in coordination with and at the direction of Individual-1." The filings indicate that Individual-1 refers to Trump.

Legal jeopardy

Trump and his legal team insist he engaged in no wrongdoing. They have offered various explanations about the payments in recent months. Speaking to reporters aboard Air Force One in April, Trump denied knowing about the payment to Daniels and said he did not know the source of the money.

In May, a few weeks after the FBI raided Cohen's home and offices, Trump and his lawyer Rudy Giuliani said the President had reimbursed Cohen through a legal retainer.

Giuliani later said the payment to Daniels was aimed at resolving "a personal and false allegation in order to protect the President's family."

That mirrors a defense used successfully by John Edwards, a two-time Democratic presidential candidate in a 2012 federal campaign corruption trial. Defense lawyers argued that $1 million in secret payments from Edwards' donors to hide the candidates' pregnant mistress were aimed at shielding the affair from his wife, Elizabeth, not voters.

Jurors acquitted Edwards on one count and deadlocked on five other charges. In the end, the Justice Department decided against a retrial.

The Cohen plea is markedly different from the Edwards case, said Common Cause's Ryan. Edwards' case lacked key witnesses involved in the payments. One donor who prosecutors allege used his money to help conceal Edwards' mistress had died by the time the trial started; the other, heiress Bunny Mellon, was 101 at the time and too frail to take the stand.

"We have a direct participant in these transactions, Michael Cohen, who has testified under oath that the purpose of these payments was to influence the election," Ryan said. "There certainly wasn't evidence like that in the John Edwards trial."

For his part, Trump says his former lawyer is not a credible witness.

"Cohen just trying to get his sentence reduced," the President tweeted Monday morning, before adding: "WITCH HUNT!"