As for the portrayals of the presidents, they weren't as bad as I expected, but then again, I had low expectations. The roles for the actors playing each president are limited to one or two scenes each. Kennedy and Reagan come off very well, Nixon is vilified, though no worse than in most histories of Watergate. None of the presidents are portrayed as being mean to staff. Although shown as played by an actor in the IMDB site, Barack Obama is not portrayed by an actor (unless I missed something, maybe it's in a deleted scene or something.) Gerald Ford and Jimmy Carter are shown only in news film.
The script will probably be more pleasing to those on the left than on the right, though I don't mean to suggest that the writers go out of their way to bash the right. It simply reflects the reality that, as many of the main characters are African-Americans living in the District of Columbia, they are therefore more likely to be Democrats and this is reflected in the film. Any contempt for the film on this basis will likely be generated within the mind of the critic rather than from the film itself. The film lets history speak for itself: from the Little Rock nine, to the freedom riders, the Kennedy assassination, Johnson's Civil Rights bills, Martin Luther King Jr., Vietnam, Watergate up to the election of the first African-American president. Much of the narrative is told through the news footage of the time.
I enjoyed this film tremendously and I'm curious to learn what the rest of you think of it.