Owen Gleiberman Chief Film CriticIf you want to meet a Republican politician who’s the ultimate poster boy for shameless apple-polishing — the kind of eager conservative loyalist who would crawl across broken glass to shine Donald Trump’s shoes — you should watch “The Swamp,” the new HBO documentary, and get a load of Matt Gaetz, a congressman from Florida who got swept into the U.S. House of Representatives by the Trump tidal wave.Gaetz is a real piece of work.