In an upcoming HBO documentary, U.S. Rep. Ken Buck paints a bleak picture not only of Congress but also of his own political party and the conservative movement in this era of President Donald Trump, before suggesting he will retire soon. “The problem with the Republican Party now is that we have such a fresh history of violating the Constitution, of violating fiscal responsibility, of violating personal accountability, that we don’t have a high ground to stand (on) and say, ‘You guys are doing the wrong thing,’ ” says Buck, a Windsor Republican and chairman of the Colorado Republican Party, in a documentary called “The Swamp.” The movie, which debuts 7 p.m.