Rampart invokes a question which, in itself, is never a good sign when it comes to filmmaking. What went wrong when the end result is much lesser than the sum of its parts? Here we have the multi-talented Woody Harrelson, in the role of a psycho LA cop, flanked by great names such as Sigourney Weaver, Steve Buscemi, Ned Beatty and Robin Wright, in a film that, for all intents and purposes, offers great material and a thrilling story. Now, subtract from this sum the fact that most of these talents are shamefully underused, and then the factors of bad writing, bad direction, complete lack of…