There’s the 32 percent of Democrats who blame “the Jews” for the financial crisis. There’s the 25 percent of African-Americans who believe the AIDS virus was created in a government lab. There’s support for state secession, which may have been higher among liberals in the Bush era than among Republicans in the age of Obama. And there’s the theory that the Bush White House knew about 9/11 in advance, which a third of Democrats endorsed as recently as 2007.

So are we a nation of potential James Lees, teetering on the brink of paranoid violence?