Guilt or Involvement??

It appears obvious from the film that he had no involvement in the assasination. He gets very emotional at this point in the film and may even start crying. Of course he may just be a good actor, but the manner in which it is presented is that he was stunned at the whole thing and that he still holds a great deal of respect for Kennedy and Johnson to this day.

Another point that should be made is that Johnson really wasn't trying to push the war in Vietnam, but felt that it was necessary even though he didn't agree with it altogether. The insight into Johnson was unexpected and completely welcomed.