Quoth the First Amendment: "Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances."
"Separation of church and state" is a common, well understood shorthand for the first two clauses of that amendment. For Limbaugh, it's a conspiracy.
"This is a modern and incorrect description of the prohibition of the establishment of a national religion," he went on.
And the left has taken this to say that religious people can not be in government. And that you can't teach something like creation in the schools while you can teach evolution because evolution isn't religion but creationism is. Intelligent design can't be taught because that's a religion, evolution is. Yet both require faith because neither can be proved.
The audience, at Widener Law School, was unsurprisingly taken aback by O'Donnell's question -- which, to Limbaugh, is a harbinger of the decline of the American empire.
"Separation of church and state is not in the Constitution, and the fact that people laughed about this is what's really scary."