Oddly, a number of those books were *assigned* reading in my schools (notably, Twain, Steinbeck, Salinger, Harper Lee, Shel Silverstein [3rd grade], Huxley, Roald Dahl, Vonnegut, and Golding).
A quick persusal of the list implies that half the books are being contested from the Right, and the other half from the Left.
We may have finally stumbled upon the Grand Unification Theory of Group Politics... Namely, both sides seek to stifle speech it deems 'offensive'.
Guy Montag, where art thou?
"Now let's take up the minorities in our civilization, shall we? Bigger the population, the more minorities. Don't step on the toes of the dog-lovers, the cat-lovers, doctors, lawyers, merchants, chiefs, Mormons, Baptists, Unitarians, second-generation Chinese, Swedes, Italians, Germans, Texans, Brooklynites, Irishmen, people from Oregon or Mexico . . . The bigger your market, Montag, the less you handle controversy, remember that! All the minor minor minorities with their navels to be kept clean. Authors, full of evil thoughts, lock up your typewriters. They did. Magazines became a nice blend of vanilla tapioca. Books, so the damned snobbish critics said, were dishwater. No wonder books stopped selling, the critics said. But the public, knowing what it wanted, spinning happily, let the comic books survive. And the three-dimensional sex-magazines, of course. There you have it, Montag. It didn't come from the Government down. There was no dictum, no declaration, no censorship, to start with, no! Technology, mass exploitation, and minority pressure carried the trick, thank God. Today, thanks to them, you can stay happy all the time, you are allowed to read comics, the good old confessions, or trade journals."
~Ray Bradbury, Farenheit 451, 1953