“For the last few years, many of these far-right groups and militias have been talking about civil war, about overthrowing the government,” says FRONTLINE correspondent A.C. Thompson. In collaboration with ProPublica and UC Berkeley Graduate School of Journalism, the new documentary “American Insurrection” investigates those responsible for recent threats and violence. Tune in or stream 4/13 on PBS. https://to.pbs.org/3jKKEOA | FRONTLINE | PBS