McConnell said he could not vote to convict Trump because he is "constitutionally not eligible for conviction" since he is no longer president. He added that a conviction would have created a dangerous precedent that would give the Senate power to convict private political rivals and bar them from holding future office.
"There should be a complete investigation about what happened," said Louisiana Senator Bill Cassidy, one of seven Republicans who voted to convict Trump. "What was known, who knew it and when they knew, all that, because that builds the basis so this never happens again."
Cassidy said he was "attempting to hold President Trump accountable," and added that as Americans hear all the facts, "more folks will move to where I was". He was censured by his state's party after the vote.
An independent commission along the lines of the one that investigated the September 11 attacks would probably require legislation to create. That would elevate the investigation a step higher, offering a definitive government-backed accounting of events. Still, such a panel would pose risks of sharpening partisan divisions or overshadowing President Joe Biden's legislative agenda.
"There's still more evidence that the American people need and deserve to hear and a 9/11 commission is a way to make sure that we secure the Capitol going forward," said Democratic Senator Chris Coons, a Biden ally. "And that we lay bare the record of just how responsible and how abjectly violating of his constitutional oath President Trump really was."
House prosecutors who argued for Trump's conviction of inciting the riot said Sunday they had proved their case. They also railed against the Senate's Republican leader, Mitch McConnell, and others who they said were "trying to have it both ways" in finding the former president not guilty but criticising him at the same time.
A close Trump ally, Senator Lindsey Graham, voted for acquittal but acknowledged that Trump had some culpability for the siege at the Capitol that killed five people, including a police officer, and disrupted lawmakers' certification of Biden's White House victory. Graham said he looked forward to campaigning with Trump in the 2022 election, when Republicans hope to regain the congressional majority. "His behaviour after the election was over the top," Graham said. "We need a 9/11 commission to find out what happened and make sure it never happens again."