He lunged at a Secret Service agent’s throat. He threw dishes during temper tantrums. And he wanted metal detectors taken away so his fans could march with guns and knives.

An astonishing portrait of Donald Trump as an unhinged and personally violent president emerged at Tuesday’s hearing of the congressional committee investigating last year’s attack on the US Capitol.

Even for a country – and a political press corps – long used to the norm-shattering of the Trump years, the picture painted of Trump at the surprise hearing was a shock to the system. The January 6 panel had promised new revelations and it did not disappoint.

“Never before in American history have we ever seen credible testimony this shocking against a president of the United States before Congress,” Michael Beschloss, a presidential historian, told the MSNBC network. “This is a day that is going to loom very large in American history.”

The star witness at the hastily arranged hearing was Cassidy Hutchinson, an aide to the then White House chief of staff, Mark Meadows. She described how Trump wanted to go to the US Capitol with his supporters on January 6 after giving a fiery speech that urged them to fight for him.

Hutchinson, 25, testified to the panel that Tony Ornato, the White House deputy chief of staff, told her that Trump had a “very strong, very angry response” when informed he would be driven back to to the White House instead.

Trump allegedly told a Secret Service agent: “I’m the effing president. Take me up to the Capitol now.”

When the agent refused, Trump tried to seize the steering wheel of the presidential limousine, known as “the Beast”. His security detail, Robert Engel, grabbed his arm and said: “Sir, you need to take your hand off the steering wheel. We’re going back to the West Wing. We’re not going to the Capitol.”

Hutchinson told the hearing that Trump then used his free hand to lunge towards Engel’s clavicle. Engel has never contradicted the account, she added.

The committee also heard how Trump erupted in fury on 1 December after his attorney general, William Barr, gave an interview to the Associated Press saying there was no evidence of widespread election fraud.

Hutchinson recalled seeing a shattered porcelain plate and ketchup on the wall of a dining room at the White House. “The valet had articulated that the president was extremely angry at the attorney general’s AP interview and had thrown his lunch against the wall.”

This was not an isolated incident. She added: “There are several times … I was aware of him either throwing dishes or flipping the tablecloth to let all the contents of the table go on to the floor and break or go everywhere.”

The account demonstrated that the coup attempt on January 6 was no anomaly but on brand for a man who seems to regard violence as sport. Trump has long been prominent in the worlds of boxing and wrestling and in a 2013 interview said of organised crime: “I have met on occasion a few of those people. They happen to be very nice people.”

During his election campaign in 2016, he told one rally crowd: “If you see somebody getting ready to throw a tomato, knock the crap out of them, would you? … I promise you I will pay for the legal fees.” At another, he said of a protester: “Get him out. Try not to hurt him. If you do, I’ll defend you in court. Don’t worry about it.”

Earlier at Thursday’s hearing, Hutchinson told the House of Representatives select committee that Trump was told people at the January 6 rally had guns, knives and other weapons and was disappointed at them being turned away.

She said: “I overheard the president say something to the effect of, ‘I don’t effing care that they have weapons. They’re not here to hurt me. Take the effing mags [magnetometers] away. Let my people in, they can march to the Capitol from here.’”

After the session, Jamie Raskin, a member of the committee, told reporters: “We had the president of the United States upset that the Secret Services and other authorities were using metal detectors for people entering his rally and he wanted those taken down so everyone could enter including people who were armed and there were official reports of people carrying AR-15s on that day.”

There was more. Hutchinson testified that, as the mob hunted Mike Pence, Meadows told the White House counsel, Pat Cipollone, that Trump was untroubled. “I remember Pat saying … ‘They’re literally calling for the vice-president to be effing hung.’ And Mark had responded something to the effect of, ‘You heard him, Pat. He thinks Mike deserves it. He doesn’t think they’re doing anything wrong.’”

And the end of the session, Liz Cheney, the vice-chairwoman, showed that witnesses have been receiving calls and messages from people close to Trump telling them that he knows they will remain “loyal” in depositions. Beschloss tweeted: “Why does this sound like a hearing investigating a Mobster?”

It all proved that, despite countless newspaper reports and books, the four years of Trump’s presidency still have the power to make jaws drop.

How bad his critics think it was, there is always another revelation around the corner that shows it was even worse. Perhaps most incredible of all, the man who sought to overthrow American democracy is the frontrunner for the Republican party presidential nomination in 2024. For the moment, at least.

Mehdi Hasan, a broadcaster and journalist, posted on Twitter: “Listening to this hearing today is yet another reminder that there is no aspect of the Trump presidency that could be written by a TV writer in a writing room. It would be ridiculed as too unbelievable and too unrealistic and too crazy.

“But it all happened. In real life.”