This new two-hour documentary is overwhelmingly about Watergate itself, not the movie it inspired – though Robert Redford and Dustin Hoffman reunite to talk, as do the reporters they portrayed, Bob Woodward and Carl Bernstein. As a Watergate recap, it’s impressively detailed even on the most complicated bits: the Saturday night massacre, the drama of the hearings, and so on. New interviews with Tom Brokaw, Jon Stewart and a surprisingly tearful Ben Stein (a former speechwriter for Ri