Reading about American constitutional law, one frequently sees the words "political thicket" (in the context of cautioning against courts becoming involved in political matters). Felix Frankfurter started it in 1946, in Colegrove v. Green, and the image has stuck. Even though I've taught the cases that fret about the "political thicket" for years and have always paid attention to Frankfurter and his idiosyncratic way of expressing himself, today was the first time I ever stopped to wonder why he wrote "thicket" instead of "jungle," the plant-based image ordinary English speakers would use (as in the cliché "it's a jungle out there"). Frankfurter often picked a fancy word where a common one would do, so no reason more than that is needed, but it occured to me that "thicket" is more descriptive of the American landscape and therefore an apt way to refer to American politics. Now I'm thinking that the name of the case, Colegrove, made him picture a thicket, so I will have to continue to ponder the enigma of Felix Frankfurter.
I looked up how many times the Supreme Court had written "political thicket" (16), "thicket" (53), "political jungle" (0), and "jungle" (27). Checking to see why a Justice had used "jungle," I ran into this choice Stevens quote (speaking of apt landscape images): "[I]t borders on the absurd to suggest that Antarctica is governed by nothing more than the law of the jungle."
"Jungle" does, however, easily beat "thicket" in the stock phrase "law of the jungle": the Court has used "law of the jungle" four times, but never "law of the thicket."