With a stemwinder at Valley Forge, Pennsylvania, President Biden has set the 2024 election in stark terms: “Democracy is on the ballot.” The dark speech forecasts a campaign as cold as the Winter of 1777, promising “freedom from fear” while hyping — and spreading — fear itself.

Mr. Biden’s speech reminds me of what comedians call a “shaggy dog story,” because the teller can add details and stretch the truth for effect. The tale of January 6, though, is already stark. Exaggerating the facts isn’t necessary and only undermines the event’s impact.

Because the behavior of Mr. Trump’s supporters on January 6, 2021, was indefensible, the only limits on describing it are those Mr. Biden chooses to set — and he sets none. The riot was also a political gift, one he can’t resist gilding to lay bare “MAGA Republicans” in an even worse light than what Americans witnessed.

Mr. Biden describes a democracy so fragile that an unarmed mob almost destroyed it. In truth, “the state of our union is strong,” a phrase President Reagan first used in his state of the union speech in 1983. No rabble, no presidential candidate, no foreign nation ought to be sent the message that it’s hanging by a thread.

“We nearly lost America,” Mr. Biden said of January 6, “nearly lost it all,” and 2024 will be a vote on whether that democracy perishes from the earth. Similar warnings peppered the speech, rhetorical flourishes that I’ve often suspected are the residual of Mr. Biden’s decades in the Senate.

A president, however, is not one of 100 in half of a branch of the federal government. As chief executive, he embodies the entire second branch, one of the three. With that responsibility, it’s wise not to be loose with words — an irony since that’s one of the many knocks against Mr. Trump.

Warming to his theme, Mr. Biden quotes Mr. Trump saying he would be a dictator “on day one.” The casual observer was given the impression of a man campaigning on absolute power. Video of the remark shows Mr. Trump’s answer was a kind of self-deprecating, humorous quip.

When a commentator, Sean Hannity, asked Mr. Trump about warnings that he’d be a dictator, the former president indulged his self-destructive impishness. “Only on day one,” he said. Millions may not want to risk that he used the qualifier in jest, but about half the nation thinks they’re in on the joke.

There’s also the fact that after all the resistance, as the Sun wrote on Wednesday, “Mr. Trump vacated the White House on January 20, as was his constitutional duty, and flew home to Mar-a-Lago. One doesn’t have to be a Trump voter to perceive that he did no more damage to the parchment than has been done by those who push the idea of a ‘living constitution,’ fiat money, or substantive due process.”

What emerged from Mr. Biden’s speech at Valley Forge is a dark picture of an America that’s only one election away from collapse. As I warned in my column this morning, by casting Mr. Trump as a dictator-in-waiting — as Mr. Biden did again at Valley Forge — it raises a question: Will he respect the results of the election if he loses?

“The 46th president will have two choices,” I wrote, “neither attractive.” He could “repudiate all the Hitler barbs” or refuse to surrender the White House to a man “he believes would be a dictator.” Neither option is good for democracy. Mr. Biden hung FDR’s portrait in the Oval Office, but he forgets that FDR was the president who warned, “The only thing we have to fear is fear itself.”

Newspapermen are taught to avoid saying “never.” America, and the Constitution, though, have survived secession, economic depressions, and World Wars. They have survived Mr. Trump once. Credit is to the Founding Fathers who, like General Washington and his army shivering at Valley Forge, secured liberty for posterity. I wouldn’t underestimate them.