Caligula revisited: Germany’s National Socialist Party came to power in 1933 thanks to an unusually charismatic Austrian-born politician named Adolf Hitler who arrogantly promised not only to make his hobbled nation great again, but also to eliminate those who did not live up to his vision of Aryan purity, most of them Jews. In short order, he created a juggernaut military and a youth movement loyal only to him. No “lesser” European state, he proclaimed, would tell him what to do. Italy’s Benito Mussolini, Il Duce, found all this very thrilling indeed and ramped up copycat efforts so that his neo-Roman Fascism could join the gladiatorial party. News that the American president — who, despite his bluster, possesses none of Hitler’s organizational skills — will hold Colosseum-like cage fights on the White House lawn as part of his 80th birthday celebrations once again places his aberrant presidency on par with its 1930s precursors. No, America is not yet a Nazi or Fascist state, but its policies, including deportations, disdain for international law, and White supremacist tendencies, put it clearly in Hitler-Mussolini territory, as does an egomaniacal leader congenitally bereft of an operating moral compass. Hitler satiated his megalomaniacal side by staging a massive rally at Nuremberg, memorably captured by Leni Riefenstahl in her propaganda documentary “Triumph of the Will.” For America’s boss it is mixed-martial arts–style cage fights Caligula, no doubt, would have enjoyed. Next perhaps will come a luxury-box Colosseum, with lions in waiting, and what’s left of national dignity auctioned off to an ascendant China avidly aware of the Robert Graves masterpiece, The Rise and Fall of the Roman Empire.