The shame of the moment is hard to process: “an assault on the most sacred of American undertakings—the doing of the people’s business,” as President-elect Joe Biden described it in an urgently scheduled press conference, just after 4 p.m. Eastern time. The President-elect, whose clear and long-substantiated victory in the Electoral College was supposed to have been tallied in the Capitol building today—a traditionally bipartisan ritual that is the last step in the certification of a new President prior to inauguration—instead had to assume the function of an acting President: calling for a “restoration of democracy, of…honor, respect, the rule of law—just plain, simple decency—the renewal of politics about solving problems…not stoking the flames of hate and chaos.”

The President-elect reminded his fellow citizens and those watching the unfolding violence around the world that the lawless extremists attacking the Capitol “do not represent the true America, do not represent who we are.”

“This is not dissent, it’s disorder,” said Biden. “It’s chaos. It borders on sedition. And it must end.”

Indeed, sedition—defined as “incitement of resistance to or insurrection against lawful authority”—it surely seemed to be. Hours earlier, at a rally apparently designed to incite, one prominent speaker—former New York mayor Rudy Giuliani—called on the crowd of Trump true-believers to resolve their disappointment over the November election by way of “trial by combat.”

The marauders, many of them armed, took those words to heart. They stormed and vandalized the Capitol building, smashing windows and occupying offices. They terrorized lawmakers in session—and the violence grew only more tragic from there: Someone shot and killed a woman inside the Capitol, according to news reports. It was, as Biden put it, “a God-awful display.”

“The words of a President matter,” said the President-elect to the man he will replace in 14 days, the man who was still silent and holed up in the White House. “Therefore, I call on President Trump to go on national television now to fulfill his oath and defend the Constitution and demand an end to this siege.”

Minutes after Biden concluded his remarks, Trump released a video on his Twitter page, which has now been removed. “We had an election that was stolen from us,” he said, repeating his oft-repeated and still-unfounded claims. He reassured his violent mob, “I love you” and “I know how you feel.” He called his perceived political enemies “so bad and so evil.” But he squeezed in a quick, “But you have to go home now.”

It was yet another reminder in a long, frightening line of reminders how unpresidential this President could be—and today’s attack on the Capitol, a rebellion not quelled until at least 6 p.m. this evening, was another reminder of how dangerous his reckless incitement can be.

“Democracy is fragile,” said Biden, “and to preserve it requires people of goodwill, leaders with the courage to stand up, who are devoted not to the pursuit of power…but to the common good.”

Let us hope that this shameful day reawakens that call to leadership. We have been too long without it.