Donald Trump ignored advisers as he spent hours watching the January 6 attack on the U.S. Capitol unfold on TV, a hearing was told.
Trump's children and other close advisers urged him to intervene and tell his supporters to stop the violence, witnesses told a congressional hearing on Thursday.
The House of Representatives Select Committee used its eighth hearing this summer to detail what members said was Trump's refusal to act for more than three hours between the end of his inflammatory speech at a rally urging supporters to march on the Capitol, and the release of a video telling them to go home.
"President Trump sat at his dining table and watched the attack on television while his senior-most staff, closest advisors and family members begged him to do what is expected of any American president," said Democratic Representative Elaine Luria.
The panel played video testimony from White House aides and security staff discussing the events of the day.
Former White House counsel Pat Cipollone was asked questions on whether Trump called the secretary of defence, the attorney general or the head of homeland security.
Cipollone answered "no" to each query.
"He's got to condemn this s*** ASAP," Trump's eldest son, Don Jr., appealed in a text message to Trump's chief of staff, Mark Meadows, while warning his legacy as president could be damaged if the violence escalated.
The onslaught on the Capitol, as Vice President Mike Pence met with lawmakers, led to several deaths, injured more than 140 police officers and delayed certification of Democratic President Joe Biden's victory in the November 2020 election.
Representative Adam Kinzinger, one of two Republicans on the committee, said Trump had no interest in calling off the rioters.
"The mob was accomplishing President Trump's purpose, so of course he didn't intervene," Kinzinger said.
Trump remains popular among Republican voters and continues to flirt with the possibility of running for president again in 2024.
But a Reuters/Ipsos poll concluded on Thursday found his standing among Republicans has weakened slightly since the hearings began six weeks ago.
Some 40% of Republicans now say he is at least partially to blame for the riot, up from 33% in a poll conducted as the congressional hearings were getting under way.
Trump denies wrongdoing and continues to claim falsely that he lost because of widespread fraud.
"These hearings are as fake and illegitimate as Joe Biden - they can't do anything without a teleprompter," Trump spokesperson Liz Harrington said in a post on his Truth Social social media site during the hearing.
The panel of seven Democratic and two Republican House members has been investigating the attack for the past year, interviewing more than 1,000 witnesses and amassing tens of thousands of documents.
It has used the hearings to build a case that Trump's efforts to overturn his defeat by Biden in 2020 constitute dereliction of duty and illegal conduct, far beyond normal politics.
A security official whose identity was shielded said some of Pence's bodyguards began to fear for their own lives.
"There were calls to say goodbye to family members," the security official said. "The VP detail thought this was about to get very ugly."
More than 850 people have been charged with taking part in the riot, with more than 325 guilty pleas so far.