On Tuesday, Michael Cohen, President Trump’s former consigliere and a man who had a talent for ostentatious indifference, walked into federal court and pleaded guilty to eight felonies. Remember during the election when he was confronted on CNN with dismal polls suggesting his candidate was losing, and he scoffed, “Says who?” That time his bravado was warranted.

But his appearance before a judge was a remarkable reversal of fortune for the man who styled himself Mr. Trump’s attack dog and fixer, a man quick with a threat of a libel suit or a promise to destroy journalists who vexed him or his boss. Mr. Cohen was forced to abase himself before a roomful of reporters, admitting to a wide range of serious wrongdoing, including tax evasion and bank fraud — while also directly implicating the president of the United States in federal campaign finance violations.

This preposterous age of manic news cycles — Mr. Cohen’s admission came on the same day that Paul Manafort, the president’s former campaign chairman, was convicted of eight counts of tax and bank fraud — weekly bombshells and improbable politics has left us deadened to amazing developments. So let me repeat it for emphasis and for history: The president’s personal lawyer pleaded guilty to a federal crime and testified under oath that the president told him to do it.

In the most explosive admissions, Mr. Cohen pleaded guilty to committing two federal campaign finance violations on behalf of — and, according to Mr. Cohen, testifying under oath, “in coordination with and at the direction of” — President Trump. The charging document describes a scheme to pay off Karen McDougal, the former Playboy model, and the pornographic film actress Stormy Daniels to buy their silence about their claims of affairs with Mr. Trump. Mr. Cohen admitted to arranging for American Media, Inc. — publisher of The National Enquirer — to pay Ms. McDougal $150,000 to keep her story quiet to protect the Trump campaign, thus causing a prohibited corporate campaign contribution.