Washington (CNN) President Donald Trump and his Republican allies in Congress this week have repeatedly sought to dismiss as trivial allegations that Trump directed hush money payments to women in potential violation of the nation's campaign-finance laws.

"If you hire an attorney to solve a problem, do you expect the attorney do it legally?" House GOP leader Kevin McCarthy asked Thursday, echoing Trump's contention that the President's former lawyer Michael Cohen bore full responsibility for any crimes. Earlier this week, McCarthy warned that there are "a lot of members who would have to leave" Congress if campaign-finance violations amounted to impeachable offenses.

But election-law experts say those arguments are getting harder to make, as the crimes outlined by federal prosecutors this week pose fresh legal risks for Trump and his campaign.

"Campaign-finance laws are serious, and people do go to jail over them," said Larry Noble, the former general counsel of the Federal Election Commission and a CNN contributor. "It's appalling that members of Congress would say federal laws aren't that serious."

Former Illinois congressman Jesse Jackson Jr., for instance, went to prison after pleading guilty in 2013 to using campaign funds to buy $750,000 in luxury goods, clothing and collectibles. In 2015, Virginia political operative Tyler Harber was sentenced to two years in prison for illegally coordinating spending between an unsuccessful congressional campaign and that of a super PAC that he helped create.

And earlier this month, a federal jury convicted Ken Smukler, a former campaign aide to Democratic Rep. Bob Brady, of making illegal campaign contributions, including a $90,000 payment to encourage a Democratic challenger to drop out of a 2012 House race. Brady was not charged and denies involvement. He is retiring from Congress

Not 'business as usual'

Campaign experts say the case involving Trump's former lawyer and "fixer" Michael Cohen bears little resemblance to the kinds of more routine snafus that frustrate lawmakers and their campaign lawyers when they navigate the nation's election rules.

Cohen was sentenced this week to three years in prison for several crimes including bank fraud, tax evasion and campaign-finance violations. Cohen and federal prosecutors have implicated Trump in the campaign-finance crimes, saying the then-Republican presidential candidate directed Cohen to make illegal, six-figure payments to two women to avoid a scandal before the 2016 election.

American Media Inc., the parent company of the National Enquirer, admitted Wednesday that it funneled one of those payments to former Playboy model Karen McDougal to protect Trump's campaign.

A non-prosecution agreement with the federal prosecutors also disclosed that AMI chairman David Pecker had met in August 2015 with Cohen and "least one other member of the campaign" to discuss how to deal with negative stories about Trump's relationships with women.

Trump was the third person in the room for that meeting, a source familiar with the matter confirmed to CNN

Richard Hasen, an election-law expert at the University of California at Irvine, said the tabloid's admission "provides corroboration" of Cohen's claims that the payments were indeed related to the election, a critical factor in establishing a violation of campaign laws.

And the revelation that Trump attended the meeting with Pecker and Cohen makes it harder for the President to claim that "he didn't know what was going on at the time," Hasen added.

"He would only be able to claim that as a legal matter, the payments don't count, or as a factual matter, that he did not understand the legality," Hasen said.

On Thursday, Trump denied any wrongdoing and insisted he did not direct Cohen to break the law in making a $130,000 payment to porn star Stormy Daniels or in arranging reimbursement for $125,000 of the $150,000 payment by AMI to Karen McDougal.

But if any laws were violated, Trump said that Cohen bore responsibility. "He was a lawyer, and he was supposed to know the law," Trump tweeted.

Later on Fox News, Trump argued that Cohen "pled guilty to something that's not even a crime" and that, as President, he's been unfairly targeted by federal prosecutors.

"What about Congress? The slush fund," Trump said in an apparent reference to a US Treasury Fund that has been used to settle workplace complaints and settlements, including claims of sexual harassment in Congress. The fund is not really a "slush fund," which implies a secret or illicit use. The amount the office spends is publicly disclosed but the details of the specific claims have not been widely known.

This week's developments represent a dramatic turn in events that have unfolded since January when The Wall Street Journal first reported that Cohen had created a limited liability company to pay Daniels for her silence just days before the general election in 2016.

Trump at first denied knowing about the payment. In May, however, he and his lawyer Rudy Giuliani revealed Cohen had been repaid through what Giuliani described as a legal retainer arrangement.

In the end, federal prosecutors say Cohen was paid a total of $420,000 by the Trump Organization through a series false invoices. The payments not only reimbursed Cohen for the payment to Daniels, but included payments to cover campaign-related "tech services" and a $60,000 bonus.

Hasen said the circumstances surrounding these payments are not typical.

Members of Congress and their campaign-finance lawyers "do a generally good job" complying with federal election law, he said. "Sometimes they may mistakes for which they pay civil fines," he said.

"What you don't see is someone denying a payment for a year, rather than 'fessing up to it and then trying to hide the payment and falsely structuring payments to reimburse a lawyer," he said.

"This is not business as usual among anyone in Congress."

Private business

Trump also has cast the payments as "private transactions," outside the reach of campaign-finance laws -- an argument shared by some Republican election lawyers in recent days.

Bradley Smith, a former chairman of the Federal Election Commission, says it's a stretch to say the payoffs were aimed solely at influencing the election.

Writing in the National Review this week, Smith said Trump had valid, personal reasons to hide the alleged affairs from public view. Among them: protecting his family from scandal and preserving his viability as a TV personality had he lost the election.

Just because an action might benefit a candidate, doesn't mean its sole purpose is to influence an election, he said.

"A candidate may intend for good toothpaste and soap, a quality suit and a healthy breakfast to positively influence his election," Smith wrote, "but none of those are campaign expenditures because all of those purchases would typically be made irrespective of running for office."

That parallels the defense former two-time Democratic presidential candidate John Edwards made when he stood trial on campaign corruption charges in 2012.

Edwards' lawyers said the approximately $1 million that Democratic donors paid during the early stages of the 2008 campaign to conceal Edwards' pregnant mistress was aimed at protecting his wife, Elizabeth, who was battling cancer, not to influence voters. The Edwardses separated in 2010 and she died later that year.

The jury acquitted Edwards on one charge and deadlocked on five other counts. The Justice Department declined to retry him.

Trump has not been charged with a crime, and the Justice Department's guidance is that a sitting president should not be indicted. Prosecutors in New York, however, could pursue charges once Trump leaves office.