In a divided nation, a divided Congress confronted a star witness from deep inside Trump world Wednesday and found a rare unity: Republicans and Democrats alike agreed that Michael Cohen, the president’s longtime lawyer and fixer, is a cravenly amoral liar.

The president’s supporters concluded from Cohen’s self-avowed record of lying to protect Trump that he cannot be believed, that his late conversion into a severe critic of Trump’s character is proof that Cohen is, as ever, in it for himself.

“You’re a disgraced lawyer. . . . You’re a pathological liar,” said Rep. Paul A. Gosar (R-Ariz.) “There’s no truth to you whatsoever.”

The president’s critics, meanwhile, looked at the same set of facts, the same confessions and apologies from a man they long considered Trump’s vicious bulldog and saw a different reality. Many Democrats decreed Cohen a redeemed truth teller, the first in a series of witnesses they plan to present to lift the curtain on a president they view as Cohen now does — as a “cheat” and a “con man.”

Republicans aren’t “afraid that you’re going to lie,” Rep. Stephen F. Lynch (D-Mass.) told Cohen. “They’re afraid you’re going to tell the truth.”

In a marathon performance before the House Oversight Committee, Cohen managed to suppress the angry, righteous, thuggish personality he has shown for years to reporters, lawyers and people doing business with Trump. Instead, he presented as a beaten-down puppy — sad, defeated and remorseful, fearful for his family’s safety, showing only flashes of the feisty, combative advocate who long took pride in his blind loyalty to all things Trump.

Cohen was a man on a mission — to reveal his employer of more than a decade not as the savvy tycoon who ruled a glitzy business empire, but as an ugly racist who lied, cheated and threatened, all to maintain his hold on power.

But Cohen also described himself as a man who has taken to walking apart from his wife and children when they’re in public. “I make them go before me,” he said. “I have fear” — of the president and of “those people that follow him and his rhetoric.”

In a country rattled by competing versions of reality and cleaved by political and cultural division, Cohen’s day-long quest for a morsel of redemption played for Republicans as a cynical attack on the president’s character and for Democrats as a vital affirmation of what many in Trump’s inner circle have until now said mostly behind the cloak of anonymity.

There was no evidence that Cohen altered a single opinion in Congress, but his stark language and harsh portrait of the president put some meat on the bones of the long-standing case against Trump.

Here, from the inner sanctum of Trump Tower, was an absolute loyalist turning on his once-beloved boss. Cohen said the president called black people stupid. Cohen chronicled Trump’s repeated requests that he lie. Cohen presented the president’s signature on a check meant to reimburse Cohen for hush money paid to the porn star who accused Trump of having an affair with her.

The brutal street fighter who would lustily browbeat reporters and lawyers on Trump’s behalf came before the nation as a penitent sad sack, a man burdened by decisions that sullied his name, sabotaged his career and hurt his family.

Republicans were having none of it.

Cohen, they repeated virtually in unison, was an inveterate liar, a bad man who simply cannot be believed about anything, and especially about the president.

“You rail on . . . the commander in chief while he’s over across the Pacific Ocean trying to negotiate a deal to make this world safer,” said Rep. Bob Gibbs (R-Ohio). “Real repentance would be go serve your time and don’t come back here and make allegations towards a man you can’t substantiate.”

Rep. Clay Higgins (R-La.), a former captain in a sheriff’s office, told Cohen that “I’ve arrested several thousand men, and you remind me of many of them,” people who were immediately remorseful but returned to their criminal behavior once they were back on the street.

Cohen, who said he threatened people at Trump’s request “probably” 500 times, now presented as a gentle, soft-spoken man with a droopy frown, a disbarred lawyer repeatedly calling for the restoration of the nation’s lost civility, a father who apologized to his children “for the pain that I’ve caused them. And I wish I could go back in time.”

Asked whether he was “a cheat,” Cohen demurred. No, he said, “a fool.”

But if Cohen sat before Congress as a man whose livelihood and reputation were shredded, he wasn’t declaring total defeat. He portrayed himself as a vital piece of Trump’s core machinery and as the inspiration for Trump’s presidential candidacy — a decision he traced to his 2011 suggestion that Trump run for office. And Cohen refused to rule out future book or movie deals, a new career in TV punditry or pursuit of elective office.

Some House members probed Cohen’s knowledge of Trump’s actions that could be illegal or dishonest, but others seemed most intrigued to get a firsthand account of just how Trump operates. They pushed for Cohen’s account of how Trump wins loyalty from those around him and how he leads advisers to take ethically dicey actions without specifically directing them to do so.

“I was so mesmerized by Donald Trump that I was willing to do things for him that I knew were absolutely wrong,” Cohen said. “Being around Mr. Trump was intoxicating.”

Cohen emphasized that he “didn’t go to work for Mr. Trump because I had to, but because I wanted to, and I’ve lost it all.”

Cohen did not always play his assigned role in the partisan stage play. He might have enhanced his credibility with some Trump supporters by several times defending the president. He said Trump has accomplished some great things in office, and he said the president would never do some of the worst things he’s been accused of.

When some Democrats fished for Cohen’s confirmation of long-standing rumors about Trump, they got nowhere. Did Cohen know about Trump abusing controlled substances? “No.” About him having been delinquent on alimony payments? “No.” About him “arranging any health-care procedures for any women not in his family?” No.

In his demeanor and language, it was clear that Cohen retains a certain respect for Trump. Always, he referred to the president as “Mr. Trump,” just as all executives do at the Trump Organization.

When Democrats asked Cohen about a long-rumored video recording that purports to show Trump hitting his wife in an elevator, Cohen confirmed that he looked into the matter and was prepared to pay to make the tape disappear. But Cohen said he concluded that no such tape ever existed and Trump could not have struck his spouse.

“He would never ever do something like that,” Cohen told Rep. Jim Jordan (R-Ohio). “I don’t see it.”

This time, Jordan seemed to believe the man he had earlier attacked as a compulsive liar.

Yet there were also places Cohen would not go. When Rep. Justin Amash (R-Mich.) asked him for the “truth that you know” Trump fears most, Cohen came up empty.

“It’s a tough question, sir,” he replied, and he turned the topic back to himself: “I’ve always tried to be a good person. . . . I’m trying very hard.”

Democrats defended the man they had spent years deriding as Trump’s unethical tool.

Rep. Gerald E. Connolly (D-Va.) said Cohen’s guilty plea and upcoming prison term did not disqualify him from revealing vital information about Trump. “This Congress has historically relied on all kinds of shady figures who turned,” providing useful and incriminating evidence, Connolly said.

Over and over, the president’s defenders hammered Cohen as an untrustworthy turncoat, an unethical lawyer who secretly recorded the words of his own client.

The Republican attack was relentless, but Cohen never blew up. He smirked and sighed and tried to speak over his harshest questioners. He shrugged and shook his head at accusations that he is a greedy profiteer who wants to make millions off his connection to Trump.

A few times, he pushed back with a brief display of his New York wisenheimer attitude. When Rep. Mark Green (R-Tenn.) pressed him on whether he planned to seek book and movie contracts after he gets out of prison, Cohen confirmed that was indeed his intention and quipped that “if you want to tell me who you would like to play you, I’m more than happy to write the name down.”

The congressman did not seem amused.

At another point, when Rep. Thomas Massie (R-Ky.) asked whether anyone had offered to pay Cohen’s attorney, Lanny Davis, for him, Cohen said, “No. Are you offering?”

While most committee members either dismissed Cohen as a liar or embraced him as a reformed truth teller, depending on their party affiliation, a few claimed to want to understand what was going on inside Cohen.

Rep. Ralph Norman (R-S.C.) said he was “trying to decide, are you really sorry for what you did, or you just got caught?” After all, Norman said, “you worked for this man for 10 years.”

The day started out bristling with anger and accusations but ended with gloom, from the witness and from both sides in the committee. No one mounted much of a defense for the president; his supporters focused instead on diminishing Cohen’s credibility.

“We’re better than this,” the committee chairman, Rep. Elijah E. Cummings (D-Md.), said. “As a country, we are so much better than this.”

Cohen dropped his head and appeared to cry as Cummings wrapped up the day: “You wonder whether people believe you. I don’t know. . . . Hopefully, this portion of your destiny will lead to a better Michael Cohen, a better Donald Trump, a better United States of America and a better world. . . . We have got to get back to normal.”