Google search for Robert A. Heinlein
Perhaps the most controversial science fiction author, he has most commonly been criticized for being "a fascist." Quite incorrect; this usually comes from people who aren't quite communists but think he's way too right-wing for their liking. I don't think real fascists would find him much to their liking either, in light of his attitudes towards individual freedom (he approved of the idea of individual freedom). Accusations of racism are also common, which is quite interesting in that the main characters of several notable books are non-white ([Starship Troopers], [The Cat who Walks Thru Walls], probably (but less clearly) [The Moon is a Harsh Mistress]).
People might be surprised to hear that in the '50s and '60s he was politically active with the U.S. Democratic party, and was definitely not Republican. His tendancies thru the '80s and '90s were fairly much "libertarian," as he felt that both "Big Government" and "Big Business" can cause "Big Problems." Indications are that, like many particularly here in Texas, he felt that the Democrats made a political shift away from their previous constituency of the "average working American" to being a special interest group for "downtrodden minorities." (Note that I am a citizen of Canada, and thus observe American politics as an outsider. Frankly, I wouldn't be thrilled with voting for any of the American parties. Too much crazy in too many ways in too many places.
My favorite science fiction book of all is his [The Moon is a Harsh Mistress] which presents a revolution coordinated by a "central" computer. The notion that a computer can truly be so intelligent is questionable; the notion that computer technology can be used to both control and to "free" people is very much the dialogue going on these days on how the Internet can and should be used. The most recent "Russian Revolution" (when Gorbachev was held captive by a would-be new military government) was powerfully influenced by the fact that people could telephone and fax news. I believe that there were also Internet Relay Chat sessions ongoing that kept people around the world in touch in real time with news reports on the events in progress. The situation in Romania was even more powerfully influenced; officials simply could not keep secret the effects of their decisions as would have been the case thirty years ago. In similar fashion, the Chinese government found themselves unable to prevent publicity of the Tien An Men Square massacre within China as a result of the fairly widespread availability of fax machines, which allowed fairly rapid and widespread dissemination of information about that event. Communications are a fundamentally powerful technology, which Heinlein perceived thirty years ago.
His books The Puppet Masters and Starship Troopers have been made into feature movies of somewhat dubious quality. In the former, much of the dialogue was reproduced fairly faithfully, but the "50's style world of the future" and the consistent "tongue in cheek" flavor of the book was lost.
The "Starship Troopers" movie, on the other hand, loses various rather important details. Tolerable is that today's F/X magic still can't simulate powered armour in a fashion that would not look "cheap." Less tolerable is that the future world is presented essentially as a "fascist utopia," complete with propaganda clips. This is certainly in keeping with peoples' prejudices as to what Heinlein was talking about in the book... Of course, about the most fascist thing truly involved in the movie is that the "intelligence" officers wear "Nazi High Command-style" uniforms, and are almost as ruthless as military men at war need to be, which, to a gullible public, makes it "fascist."
The military "tactics" presented in Starship Troopers are, as is standard in Hollywood films, stupendously stupid. Circles of troops around bugs, guaranteeing friendly fire deaths, and ships following one another so closely that any error in navigation will lead to them running into one another, killing more of their own people by incompetence than the "Bugs" could ever do by intent.
[Double Star] would probably make a pretty nifty movie that wouldn't require billions of dollars worth of FX work...
In his later years, he somehow got into a quite bizarre "rut" (pun intended) where he considered the wonders of upcoming possible "gene therapies" that would make the dangers of consanguinity go away.
Which turned into quite pathologically bizarre forms of "family arrangements." With a whole lot of [Oedipus Rex] gone strangely awry.
It would have been one thing if it had been a situation of " Let's explore, in this one book, what happens if the genetic taboos surrounding incest go away." Unfortunately, from roughly [ Time Enough for Love] on, he kind of really rather over-focused on that area.
Five of his last nine novels attested to the steadily increasing sexual bizarreness of the "Lazarus Long" family, with his last novel, [ To Sail Beyond the Sunset] being quite dramatically perverse. I can't fathom where the inspiration for it all would have come from; it's probably a happy thing that he had no children.