“One Battle After Another,” with its opening scene involving a military-run concentration camp for rounded-up immigrants, its colossal second half centered on organized resistance to help immigrants avoid government raids, and its vision of a cabal of white (and Christian) supremacists holding secret sway in Washington, was practically torn from the headlines in advance. Its vision of indignation and resistance lurked behind every one of O’Brien’s thinly veiled jokes about Donald Trump (whose name was never mentioned) and his reference to “chaotic, frightening times,” and behind Jimmy Kimmel’s gag on the muzzled media of “North Korea and CBS,” and echoed the acceptance speech of David Borenstein, a co-director of “Mr. Nobody Against Putin” (which won Best Documentary Feature), who explained, correctly, that his film shows the authoritarian outcome of compromise, complicity, and government co-option of media. “One Battle After Another” is a movie of notable artistry, indeed one of the year’s best, but its triumph is less aesthetic than political.