HOURS AFTER Sen. James Lankford’s speech challenging Arizona’s electoral college vote was interrupted as a mob of President Trump’s supporters stormed the Capitol, the Oklahoma Republican returned to the floor Wednesday night with a welcome, and far different, message. “We’re the United States of America,” he said. “We disagree on a lot of things, and we have a lot of spirited debate in this room. But we talk it out, and we honor each other — even in our disagreement. That person, that person, that person” — here the senator gestured to other senators, presumably of the other party — “is not my enemy. That’s my fellow American.”

We can rue that it took such a horrific event to remind Republicans such as Mr. Lankford of the foundational and precious values of our democracy, values undermined by their support for the president’s bogus claims about an election he lost. But we can also hope that the event will jolt them away, for the long haul, from Mr. Trump’s toxic politics of inflaming — not healing — the divides between Americans. That will require repudiating not only Mr. Trump himself but also his politics of untruth and demonization.

That Republicans and Democrats came together late Wednesday to renounce the violence that Mr. Trump had incited and condoned was both heart-rending and uplifting. “I was shaken to the core as I thought about the people I met in China and Russia and Afghanistan and Iraq and other places who yearn for freedom, and who look to this building and these shores as a place of hope. And I saw the images being broadcast around the world, and it breaks my heart,” said Sen. Mitt Romney (R-Utah), who has been a pillar of principle while much of his party caved to the whims of a dangerous president.

But an even more powerful coda to a day that was filled with so much shame and disgrace is how the men and women of Congress rallied to return to the halls that had been sullied by Mr. Trump’s hooligans to fulfill their constitutional duty to certify the election of President-elect Joe Biden and Vice President-elect Kamala D. Harris. “To those who wreaked havoc in our Capitol today, you did not win. . . . Let’s get back to work,” said Vice President Pence, who had earlier made clear he would not go along with Mr. Trump’s demands that he throw out the electoral results.

Mr. Trump’s imminent departure will not undo the damage to our democracy that culminated with Wednesday’s violent assault on the Capitol. While Mr. Lankford and several other Republican senators opted to drop their ill-advised objections to electors of some states, others — most notoriously Sen. Ted Cruz (Tex.) and Sen. Josh Hawley (Mo.) — and more than 100 Republicans in the House voted against certifying results for Mr. Biden and Ms. Harris. They “will forever be seen as being complicit in an unprecedented attack against our democracy,” as Mr. Romney said.

During his campaign and since winning the election, Mr. Biden consistently has vowed to serve all Americans, not just those who voted for him. That will be a welcome change, but healing the divisions of the past four years will be a long-term, difficult process. Mr. Biden will have to do more than mouth the right words — he will have to reach across the aisle in a true spirit of citizenship and cooperation. And we hope that the Republicans who were confronted with the harm that words can do as they raced from Wednesday’s angry mob keep Mr. Lankford’s observation at the forefront: “We’re the United States of America . . . even in our disagreement. That person, that person, that person is not my enemy. That’s my fellow American.”

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