Chaos engulfed the Capitol on Wednesday as a faction of Republicans sought to overturn President-elect Joseph R. Biden Jr.’s victory in Congress and a group of protesters loyal to President Trump tried to storm the building, demanding to be heard.
Around 2:15 p.m., the proceedings ground to a halt as security rushed Vice President Mike Pence out of the Senate chamber and the Capitol building was placed on lockdown, with senators and members of the House locked inside their chambers.
The extraordinary day in Washington laid bare deep divisions both between the two parties and within Republican ranks, the ceremonial counting of electoral votes that unfolds every four years in Congress was transformed into an explosive spectacle, with President Trump stoking the unrest.
“This is what you’ve gotten, guys,” Senator Mitt Romney, Republican of Utah, yelled as the mayhem unfolded in the Senate chamber, apparently addressing his colleagues who were leading the charge to press Mr. Trump’s false claims of a stolen election.
A group of Republicans led by Senator Ted Cruz of Texas objected early Wednesday afternoon to the counting of Arizona’s electoral votes, lodging the first of several extraordinary challenges to its outcome and forcing a two-hour debate in the House and Senate over Mr. Trump’s reckless election fraud claims.
“I rise for myself and 60 of my colleges to object to the count of the electoral ballots from Arizona,” said Representative Paul Gosar, Republican of Arizona. His objection was met with widespread applause by Republicans gathered on the floor of the House of Representatives for the joint session.
Bipartisan majorities in each chamber were prepared to turn back that challenge and others and formalize Mr. Biden’s victory. But the marathon session promised to be a volatile final act of the Trump presidency, with Mr. Trump — unwilling to cede the limelight or his fantasy of victory — transforming a moment of Democratic triumph into a day of defiance by summoning supporters to his backyard for an airing of grievances.
“We will never give up. We will never concede. It doesn’t happen,” Mr. Trump told a gathering of die-hard fans at the Ellipse behind the White House. He urged them to go to the Capitol to register their discontent, not long before a group of protesters breached barricades outside the edifice, clashing with police.
By using the proceeding as a forum for trying to subvert a democratic election, Mr. Trump and his allies are going where no party has since the Reconstruction era of the 19th century, when Congress bargained over the presidency. The effort had already badly divided the Republican Party, forcing lawmakers to go on the record either siding with the president or upholding the results of a democratic election.