Michael Cohen, the longtime personal lawyer for President Trump, in New York in April. (Seth Wenig/Associated Press)

Bob Bauer, professor of practice at New York University Law School, served as White House counsel under President Barack Obama from 2010 to 2011.

President Trump and his longtime lawyer Michael Cohen have certainly made a mess of their $130,000 payment to adult-film actress Stormy Daniels. In both the clumsy management and their changing explanations of the transaction, they have ignited a debate over whether the payment and their failure to report it violated federal campaign-finance law.

Now, under apparent pressure from the Office of Government Ethics, the president’s lawyers dropped a note into the president’s personal financial-disclosure reports about the payment, denying it was a reportable liability and asserting it was included “in the interests of transparency.” The Office of Government Ethics has notified the Justice Department of the reporting issue, raising the possibility of legal exposure for the president.

But the time and energy Trump critics have devoted to this issue has always been misplaced. Whether the Daniels payment is a financial-disclosure matter or a campaign-finance violation is largely a distraction; the more compelling and consequential issue is the Trump-Cohen relationship.

Cohen and Trump could eventually be found to have run afoul of campaign-finance law on the theory that, because Cohen’s payment on Trump’s behalf was motivated exclusively by political rather than any personal or family considerations, it was a campaign contribution that exceeded legal limits and should have been reported. But the case could well go the other way. The Federal Election Commission is generally disabled by partisan divisions: If Republicans are interested in blocking enforcement, they will attempt to show that the case against Trump is no stronger on the element of motive than in the failed case brought against former senator John Edwards (D-N.C.) over money paid by benefactors to support his mistress and child during the 2008 presidential campaign. These same factors present challenges in meeting the more demanding requirements for a successful criminal prosecution.

The personal financial disclosure may be a similar dead end, unless new facts emerge. Trump will likely assert that he did not learn of the Daniels payment until Cohen demanded reimbursement. And given Trump’s odd account that he repaid Cohen for his services “sometimes” and not others, he may well argue that he did not, in the first instance, recognize an obligation for the Daniels payment. Moreover, Trump’s lawyers might think noting the payment on the personal financial disclosure this year could work to his advantage — underscoring his stand that it was a personal payment and not a campaign expenditure.

At any rate, the campaign-finance issue and Office of Government Ethics issues would be considerably less interesting to prosecutors than other features of the Cohen-Trump relationship. Rudolph W. Giuliani, Trump’s lawyer, said earlier this month that Trump’s “reimbursement” was in the neighborhood of $470,000, considerably more than three times the sum paid to Daniels. For some reason, it was also made in installments, and while it is not clear when all the payments were made, at least some occurred after the inquiry by special counsel Robert S. Mueller III began. The arrangement cries out for investigation, which media reports indicate is already underway.

Cohen also allegedly received millions of dollars from other sources with interests before the government, raising the question of what Trump knew about this income; whether any official actions were taken to facilitate Cohen’s business arrangements; and who, other than Cohen, may have had the benefit of the payments. Moreover, this road, too, leads to Moscow: One source of Cohen income was reportedly a Russian oligarch with close ties to President Vladimir Putin.

In this context, the campaign-finance allegation involving the $130,000 payment pales in significance. The ever more curious arrangements with Cohen may be part of a larger — and to the president, more dangerous — story of how and with whom he did business, as well as what part the Russians might have played.

Perhaps this is the reason Giuliani has publicly focused on the campaign-finance issue over the Trump-Cohen relationship. He may think he can win it, and the president is looking for wins he can tout as he seeks to dismiss the “witch hunt.” It is far less threatening than questions of bribery, extortion, mail or wire fraud, or direct or indirect indebtedness to a foreign power.