Of all of tonight’s TV events, this is the one I’m anticipating most eagerly. Last night, ABC presented a two-hour special on the Watergate scandal, and it was very clearly structured, and at times unexpectedly emotional. Tonight, MSNBC covers similar ground, but through a particularly fascinating prism: the movie made, starring Robert Redford and Dustin Hoffman, who played Washington Post reporters Bob Woodward and Carl Bernstein in All the President’s Men. “Arguably the