I had some suspicion about this, based on the reaction I get from my students when I teach the second half of WLIT at my rocky little university. That's the semester we hit 18th and 19th century American texts, and I have to talk a bit of American history. Certain homeschooled students always want to argue with me about what "really" happened in American History -- or, worse, they don't argue; they sit smirked, clearly having been warned by their parents that this would happen: that their socialist liberal professors would be feeding them these warped liberal lies about America.
Since I never am, you know -- since I'm always giving them the bare-bones straight-up version of what happened -- it's a lit class, I don't have time for interpretation, I barely have time for the facts -- this has always puzzled me.
But that's because I didn't know that this sort of crap was what they were being fed.
Having been fed a steady diet of propaganda and preaching, I suppose they don't know how to hear anything else.