In Savage's warped, Manichean mind, the book is an anti-liberal parable.
I read Farenheit 451 as an apolitical adolescent and my distinct impression was that the book was anti-censorship, period. The villains in the book aren't liberals, nor are they conservatives, they are people who would censor thought. As Bradbury himself has put it, "I meant all kinds of tyrannies anywhere in the world at any time, right, left, or middle."
There is also the motif - recurrent in the literature of Bradbury - of how advances in technology might shorten attention spans and lead to a loss of interest in great literature.
At the time the book was published anyone reading it would have had a hard time not recalling the book burning of the explicitly anti-liberal Nazis or the era of McCarthyism. While I see that Bradbury now claims the book is more about the second motif than outright censorship, the fact remains that the book contains a powerful message of the wrongness of censorship regardless of its source.
But, again, for Savage, villainy, tyrrany, and oppression are by definition liberal. To millions of his listeners Savage is portraying "liberals" as an oppressive, culture destroying force of moral depravity.
Liberalism is, in essence, the HIV virus, and it weakens the defense cells of a nation. What are the defense cells of a nation? Well, the church. They've attacked particularly the Catholic Church for 30 straight years. The police, attacked for the last 50 straight years by the ACLU viruses. And the military, attacked for the last 50 years by the Barbara Boxer viruses on our planet.Now, to many people they are going to hear that and instantly recall classic fascist propaganda of Nazi Germany. Yet since Savage has already defined fascism, and evil in general, as a "liberal" phenomenon he's incapable of noticing his own extremism.