Yeah, it's a near certain
. d'man must've read some Brit Lit, probably late 19th or early 20th Century ... or maybe heard it in some older movie. I'm sure there are plenteous Americans - including Libs/Progs - who've never heard that usage of "constitutional", but I think most would recognize the
phrase "morning constitutional" as not referring to the legal document. And given how carelessly "constitutional" is used among Libs/Progs, I'm sure there are some who would both be unfamiliar with that usage of "constitutional"
and become argumentative. Idiots aren't isolated in special corners by themselves.