I think Glenn Close or Meryl Streep would make a good Hillary, with Will Smith doing an excellent Obama. Harrison Ford could be Bill Clinton with Tom Cruise as Edwards and Julia Roberts as his cancer stricken wife. On the other side, Tom Hanks would be Guiliani, Jack Nicholson for Bush, but I am a bit stuck on the rest.
If this movie had been scripted five years ago, it would have sounded like a far fetched farce. But, truth is wilder than fiction and the candidates make great movie material and a few oscars could be in the works.