Calls Grow for Commission to Investigate Capitol Riot

“We need a 9/11 Commission to find out what happened and make sure it never happens again, and I want to make sure that the Capitol footprint can be better defended next time,” Senator Lindsey Graham, Republican of South Carolina, said on “Fox News Sunday.”

In the House, rank-and-file lawmakers in both parties have introduced legislation that would establish a commission, with some Democrats proposing a broader examination of the federal government’s response to domestic terrorism and violent extremism.

“We will have an after-action review,” Speaker Nancy Pelosi of California told reporters late last month. “There will be a commission.” She has since been briefed repeatedly by retired Gen. Russel L. Honoré, who has been tapped to examine security on Capitol Hill, which remains surrounded by fences lined with razor wire and under the watch of National Guard troops.

“In the near future, Congress needs to smartly transition to a more sustainable security presence,” Senator Mitch McConnell of Kentucky, the minority leader, said in late January. “Keeping the Capitol safe cannot and will not require huge numbers of uniformed troops and vast systems of emergency fencing to remain in place forever.”

Democrats, who abruptly dropped what had been a successful demand for witnesses during the final day of the trial on Saturday, framed a possible commission on Sunday as a way to not only understand the failures that had led to the breach of the Capitol but also to underscore Mr. Trump’s role in the events.

“There’s still more evidence that the American people need and deserve to hear,” Senator Chris Coons, Democrat of Delaware, said on “This Week,” adding that a commission would “make sure that we secure the Capitol going forward and lay bare the record of just how responsible” Mr. Trump was for the attack.

Before the impeachment proceedings, there had been discussion of a bipartisan censure resolution in lieu of a trial. But lawmakers quickly abandoned the idea as the trial moved forward, in part because Democrats had demanded stronger language than what Republicans were comfortable with. Asked about the chances for a resolution intended to keep Mr. Trump from running for office again, Senator John Thune of South Dakota, the No. 2 Republican, said, “I don’t think that’ll go anywhere.”

“Every senator has had the opportunity to express his or her views,” said Senator Susan Collins, Republican of Maine, who had been involved in the discussions.

Ms. Pelosi, speaking a news conference on Saturday, declared such a resolution to be “a slap in the face of the Constitution.”

“We censure people for using stationery for the wrong purpose,” she said. “We don’t censure people for inciting insurrection that kills people in the Capitol.”