Matt Yglesias makes a good point about the current crop of reactionary science fiction stories:
As a result, you get an odd mishmash in the New Right Dystopianism. Liberal weakness is supposed to lead to jihad run amok. But they want to make liberals rather than jihadis the real bad guys for emotional reasons so the liberals need to be tough and repressive. But if the liberals are so tough, why are the jihadis run amok? It's well known, after all, that jihadis don't like liberals (feminists, gays, etc.) very much. If the jihadis are strong, they kill the liberals, not leave them around to repress conservatives. And if the liberals are strong enough to repress conservatives, they should fight the jihadis. The upshot is dystopias that are not only "implausible" but that don't really make sense. If your complaint about liberals is that they're too hesitant to curb individual liberties in order to attack the enemies of the state, you can't very well spin a dystopia about repressive "Coulter Laws" and so forth.
Heavy-handed EPA regulations, or onerous FICA taxes (12 percent of GDP on entitlements!) sure, but that's a different kind of ball game. At the end of the day, everybody knows that if it came down to an armed conflict, the conservatives would win. Which leads to Dave's point -- these books aren't dystopian at all, they're wish fulfillment about a world in which the right gets a legitimate rationale for battling liberalism through brute force.
Orson Scott Card has apparently gone off the deep end pressing this agenda. Ender's Game is a masterpiece, but he's been flogging a right wing agenda for years. His latest offering, Empire, is apparently an exercise in reactionary revenge fantasy.
But it's not just Card. For my money, Frank Herbert was always kind of reactionary, and Robert Heinlein wrote an homage to facism in Starship Troopers (though one friend insists that it's meant to be satire). In fact, much good science fiction and fantasy is reactionary, or at least conservative in tone, in theme, and sometimes in overt argument. J.R.R. Tolkien was a serious reactionary, longing for the bucolic rural England that existed (for him at least) before industrialization and automobiles. C. S. Lewis's view of women was retrograde, at best. And don't let's get started on Michael Crichton!
On the left, you don't get much. George R.R. Martin seems to lean left, based on some posts on his blog. Michael Morcock is an anarchist, as arguably so was Fritz Leiber. Of course, the world of Star Trek is a liberal utopia, but Star Wars, on the other hand, is not.
Perhaps it is the cynicism of our age. We either look romantically to the past or with skepticism on plans for a better future. Perhaps it is a somewhat pessimistic view of human capabilities -- republics fall, empires rise, noble ideals fall apart in the face of harsh reality.
Another way of looking at it is that these writers usually write good to great science fiction and fantasy, and if they don't let their agenda govern their narrative too much (I'm looking at YOU Orson!), it can be great fun to read even when you don't subscribe to the political agenda being pushed, whether from the left or the right.