Commentary If President Joe Biden’s disorderly and lethal Afghanistan withdrawal was the moment that fractured voters’ regard for him, then his vicious Atlanta speech last week may be the moment that defines his presidency. Speaking Tuesday at Morehouse College and Clark Atlanta University, Biden uttered venomous, brutal accusations lacking factual basis. His shouting-in-the-wind delivery was inexplicable, and his decision to lash out at members of his own party—Sens. Joe Manchin and Kyrsten Sinema—appears to have only strengthened their resolve not to give in to his demands. Biden called those who disagree with his political views on legislation “domestic enemies.” He compared them to Confederate President Jefferson Davis and former Alabama Democratic Party Committeeman and ardent, violent segregationist Bull Connor. In American politics, that is about as divisive as one can get—at least he didn’t mention Hitler. Biden bears no resemblance today to the man who ran for president, pledging over …