The essence of what happened on Jan 6, 2021, is well-known, if still shocking to recall. A mob stormed the Capitol in Washington in an effort to prevent Congress from certifying Mr Joe Biden's election victory. Four people in the crowd died that day, and five police officers in its aftermath.
Members of Congress had to be rushed to a secure location in a basement. Rioters erected a mock gallows and chanted "Hang Mike Pence". And the man who inspired all this was the president himself, who had urged his followers to help overturn his election defeat. As the Republicans' leader in the Senate, Mr Mitch McConnell, told the Senate a few weeks later, Mr Donald Trump was "practically and morally responsible" for the events of that day: "The people who stormed this building believed they were acting on the wishes and instructions of their president."