(CNN) Michael Cohen 's quest for redemption drew Americans into the mob-like world of Donald Trump . The President's former personal lawyer has painted a cruel and unseemly picture, shocking even with the nation's senses dulled by years of Trump-induced controversy.

In a theatrical day of congressional testimony Wednesday that will become an iconic moment of Trump's presidency, Cohen -- who is about to go to prison -- turned on his ex-client with the world watching.

He made a case that after spending a decade inside Trump's world, he knew the President better than anyone -- seeking to provide context for the flurry of investigations and claims of crimes and wrongdoing surrounding the President.

He sketched a stunning portrait of Trump's organization and conduct in what turned into an extraordinary and unprecedented daylong indictment of the character of a sitting President.

It was either the betrayal of a proven liar who is making up tales to save himself or the courageous act of an unlikely hero rising above his dirty past to provide a national service, depending on which side of the committee room lawmakers sat on.

According to Cohen, Trump's empire was awash in activity that needed a fixer. Cohen told the House Oversight Committee that he now bitterly regrets he blindly took that role, which will ultimately deprive him of his freedom.

"My loyalty to Mr. Trump has cost me everything," Cohen said, in an apparent message to a former patron who was likely watching on the other side of the planet, during his visit to Hanoi, Vietnam.

Trump, for his part, answered a single question about Cohen after his summit with North Korean dictator Kim Jong Un, by slamming Democrats for holding a hearing and calling his former fixer a liar.

"He lied a lot," Trump said. "He lied about so many different things."

In Trump's world, the boss knew everything that went on, according to Cohen. Henchmen like Cohen came to know by osmosis what the big man wanted. His currency was threats. And bad tabloid news stories were bought up -- even if they weren't true -- to stop them from sullying Trump's personal image.

There was one law of the Trump jungle that everyone came to understand, including Cohen, in his years as the right hand of the titan of Trump Tower.

"Everybody's job at the Trump Organization is to protect Mr. Trump," he said.

Ominous news for Trump

Wednesday's hearing, which played out amid fiercely partisan scenes, contained revelations that hinted at future and deeper legal exposure for the President. Most notably, Cohen produced a personal check for $35,000 that Trump signed while in office that appears to show that the President reimbursed him for hush payments he made to women who claimed affairs with the then-GOP nominee.

Cohen has already admitted paying off the women in an infringement of campaign finance law. If it is proved that Trump -- who has denied having affairs with the women -- knew he was breaking the law, the President could be in serious trouble, even after he leaves office.

Cohen, a former confidant turned accuser, also revealed that prosecutors in New York were probing Trump's organization for alleged illegality in a previously unpublicized case, underscoring the potential that the biggest threat to the President may come not from special counsel Robert Mueller but from the hard-charging US Attorney's Office for the Southern District of New York.

"I think it's ominous news for the President," said former southern district prosecutor Elie Honig on CNN.

Cohen also claimed that he had overheard a call in which Trump's longtime political adviser Roger Stone told the then-GOP nominee in 2016 that WikiLeaks was due to dump a new trove of emails that would be damaging to Hillary Clinton.

And he said Trump knew in advance about a 2016 meeting between a Russian lawyer and his campaign team designed to deliver "dirt" on Clinton.

Since Trump previously told Mueller in sworn written answers that neither of those statements were true, he could be in legal and political jeopardy if Cohen or prosecutors can provide corroboration of Cohen's claims.

It's not all bad for the President

Cohen's appearance offered a window into parts of the Russia investigation that the buttoned-down special counsel investigation has yet to provide. But the testimony also cast doubt on some reports that had suggested vulnerability for Trump.

For instance, Cohen testified that he had never been to the Czech Republic, potentially knocking down one of the accusations in the Steele dossier, a document of raw intelligence leads that purported to show that Trump was compromised by Russia.

He also said he did not believe a rumored videotape of Trump striking his wife, Melania, in an elevator existed. And he said that in any case, the President would never do such a thing.

Cohen may have tarnished his own credibility when he insisted he never wanted a job in the Trump White House. Multiple reports by CNN and other media suggest that he was not telling the truth.

"I see a guy who worked for 10 years is here trashing the guy he worked for 10 years, didn't get a job in the White House, and now you're behaving just like everyone else who's got fired or didn't get the job they wanted," Rep. Jim Jordan, an Ohio Republican who's a key Trump ally, told Cohen.

It was not immediately clear if Cohen's day in the spotlight would bolster the arguments of Democrats who already favor impeachment, since he did not have smoking gun evidence of collusion between Trump aides and Russia.

And that omission gave Republicans a political opening.

"House Democrats and Michael Cohen put on a circus that was full of lies and uncorroborated allegations," said Republican National Committee Chairwoman Ronna McDaniel.

'I am ashamed'

JUST WATCHED Cohen: Lying to first lady is one of my biggest regrets Replay More Videos ... MUST WATCH Cohen: Lying to first lady is one of my biggest regrets 00:49

But if Cohen is to be believed, thuggish, corrupt and even immoral behavior was endemic in Trump's inner circle before and during his run for president in 2016.

"I am ashamed because I know what Mr. Trump is. He is a racist. He is a conman. He is a cheat," Cohen said in his opening statement.

In a startling exchange with Democratic Rep. Jackie Speier of California, Cohen said he had been directed by Trump to threaten people probably 500 times.

According to his testimony, lying came as easily as breathing.

"Every day, most of us in the room coming in ... we were going to lie for him on something. And that became the norm, and that is exactly what is happening now in this country," Cohen said.

Complaining that Trump now calls him a "rat," Cohen described an atmosphere of oppressive malice in which Trump's instructions were so obvious that they did not need to be spelled out.

"He doesn't tell you what he wants," Cohen said, when asked whether Trump had coached him to lie to Congress in a previous appearance, one of the offenses for which he will begin a three-year jail term in May.

"I know what he means because I have been around him for so long," said Cohen, saying Trump created a "party line" that everyone around him must reject any accusations of collusion with Russia. He also said the President's lawyers had reviewed and edited the testimony at issue -- another serious charge.

Democratic Rep. Gerry Connolly of Virginia became the latest Washington figure to reach for a Mafia comparison when describing the events in Trump's inner circle, defending Cohen from GOP attacks.

"This Congress historically has relied on all kinds of shady figures who have turned," Connolly said. "One of the most famous led to the decapitation of organized crime families in America: Joe Valachi."

"He was a witness, and he committed a lot worse crimes than you are convicted of," said Connolly, pointing directly at Cohen while referencing 1960s congressional hearings that lifted the lid on Mafia activities.

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Preet Bharara, a former US attorney for the Southern District of New York who's a CNN senior legal analyst, said the accounts of Trump's apparently veiled instructions to Cohen were "the kind of thing you see in mob cases."

"It's the kind of thing you see in environments in which people do bad things but they don't want to be on the hook and on the record as asking someone to do a bad thing. It happens all the time," Bharara said on CNN's "The Situation Room."

Cohen also testified that everything came from the top in the Trump Organization, when he claimed that the President had long inflated or deflated his company's assets -- for example, to make extravagant claims about his wealth, to get bank loans or in insurance claims.

"Everything was done with the knowledge and at the direction of Mr. Trump," Cohen said. His comment could undermine Trump's denials that he had known anything about the many meetings between his aides and Russians.

Since Cohen has likely told everything and more that he said Wednesday to Mueller and other prosecutors with whom he has been cooperating, Trump's exposure could be acute.

And claims by Republicans that Cohen cannot be trusted were partially undermined by the fact that if he is proved to have lied in Wednesday's hearing, he risks having time added to his sentence.

After the hearing, a tired Oversight Chairman Elijah Cummings delivered a verdict that may augur a fateful moment in American history when he was asked whether Trump may have committed a crime in office.

"It appears that he did," the Maryland Democrat said.