A crack team of investigative reporters exposes a sitting president’s cowardly machinations to avoid Vietnam. You’re probably thinking a satisfying, speak-truth-to-power yarn, but this is closer to All the President’s Men with the bad guys winning. It’s the frustrating, true account of how the story then blew up in their faces, ultimately ending the careers of CBS veterans Dan Rather and Mary Mapes, his “60 Minutes” producer. Robert Redford does a good Rather, but it’s Cate Blanchett’s portrayal of a consummate professional coming apart at the seams that propels this idea-driven drama. (125 min)