David Frum with a bit of the classics explaining Biden and Trump. It’s good: Two political myths inspired the dreams and haunted the nightmares of the Founders of the American republic. Both these foundational myths were learned from the history and literature of the ancient Romans. Cincinnatus was the name of a man who, the story went, accepted supreme power in the state to meet a temporary emergency and then relinquished that power to return to his farm when the emergency passed. George Washington modeled his public image on the legend of Cincinnatus, and so he was depicted in contemporary art and literature—“the Cincinnatus of the West,” as Lord Byron praised him in a famous poem of the day. Against the bright legacy of Cincinnatus, the Founders contrasted the sinister character of Catiline: a man of depraved sexual appetites who reached almost the pinnacle of power and then exploited populist passions to overthrow the constitution, gain wealth, and pay his desperately pressing debts. Alexander Hamilton invoked Catiline to inveigh against his detested political adversary, Aaron Burr: President Joe Biden’s speech last night adapted the story of Cincinnatus: “Nothing, nothing can come in the way of saving our democracy,” he said. “That includes personal ambition.” By presenting the next election as a stark choice between, on the one side, “honesty, decency, respect, freedom, justice, and democracy” and, on the other side, the opposites of those things, Biden cast his chief political adversary in the ancient role of Catiline. Biden’s act of renunciation gives power to his words of denunciation. By demonstrating that he…