The jury is still out on whether 21st-century politics has reached a point beyond parody, but the one-note satire “Mister America” proves that it’s still possible to get laughs out of a single gag — and just as possible to belabor the joke.

The comedian Tim Heidecker (“Tim and Eric Awesome Show, Great Job!”) stars as, well, Tim Heidecker, who for purposes of this movie is a first-time campaigner. Tim is mounting an independent challenge to the San Bernardino County district attorney ( Don Pecchia ), who had previously tried to convict him in more than a dozen deaths. (A bad-drugs incident at an electronic dance music festival has gotten Tim dubbed the “vape killer” by the press.)