“Defenestration” is foreign enough to American politics to be viewed figuratively. Wouldn’t we all want to toss all the Rats and most of the Rinos out a window, figuratively speaking, and it would be fine to us if they landed on feather pillows as long as they stayed out. But the explanation was bizarre. These lefties haven’t even passed Infiltration 101.
But more to the point, the media will certainly bother to check out what it means, if they saw the sign, and it does mean to throw someone out a window to their death, literally. There is no figurative meaning, really, like there is with "decapitate." It could conceivably be used in a clever way by an original writer, but that does not mean it has a figurative meaning.
I could just picture myself trying to explain all of this to the cops, so I gave up.