It’s en vogue for enraged liberals to compare Trumpism to Argentine Peronism, wielding the analogy as a warning about the potential apocalypse that they fear is about to engulf us. Most recently it was Larry Summers, a member of the Democratic establishment for decades, who took to Twitter to declare: “I worry about the Argentinization of US government.” Summers sent the tweet after President Trump accused Democrats of treason and the media reported on the president’s childish wishes for a military parade. He employed a standard characterization of Peronism as an authoritarian movement, a familiar depiction that no doubt had...