President Biden is treading the campaign trail, and the 79-year-old is feeling rhetorically frisky. Speaking at an event for Democratic donors, Mr. Biden thundered, “it’s not just Trump, it’s the entire philosophy that underpins the — I’m going to say something — it’s like semi-fascism.” He also labeled “the MAGA Republicans” a “threat to our very democracy” who “refuse to accept the will of the people” and “embrace political violence.”

Asked about the president’s remarks, his press secretary, Karin-Jean Pierre, explained, “I was very clear when laying out and defining what MAGA Republicans have done. And you look at the definition of fascism and you think about what they’re doing in attacking our democracy.… I mean, that is what it is. It is very clear.” Contrast that with historian Ian Kershaw’s evaluation that “trying to define ‘fascism’ is like trying to nail jelly to the wall.”   

It takes no courage to be against fascism, or its nickel-plated variations. It is Europe’s toxic fruit, if that’s the word for screaming masses and goose-stepping thugs. The word itself first emerged among the Etruscans in reference to a bundling of sticks around an ax, a totem used by magistrates to symbolize their authority. It was picked up by Mussolini, and, from Il Duce, was passed to Berlin, accruing vast crimes to its ledger. 

Which brings us to “Godwin’s Law.” The Oxford English Dictionary in 2012 codified “Godwin’s Law” as the syllogism that “as an online debate increases in length, it becomes inevitable that someone will eventually compare someone or something to Adolf Hitler or the Nazis.” Which is what Mr. Biden just did. Whoever does this first, goes a corollary attributable to Mr. Godwin himself, loses the argument. 

The “semi-fascist” slur comes as Mr. Biden is enjoying a second wind, evidenced by a small uptick in his poll numbers, a downward swerve in gas prices, and the passage of a law to increase prices, the Inflation Reduction Act. Evidence for a “red wave” is shrinking. No one would urge Mr. Biden to run on his own record. Yet if he runs on the idea that Americans are fascists, he’ll repeat Secretary Clinton’s “basket of deplorables” error.

This has been a summer of bitter partisan discord, marked by the January 6 committee’s televised and incendiary hearings and punctuated by the sight of the FBI raiding President Trump’s compound at Mar-a-Lago. America is already riven, without the commander in chief lambasting his fellow citizens. Mr. Biden’s Inauguration Day pledge to end our “uncivil war” stands in stark contrast to what sounded to our ears like a battle cry.