The difference is that nobody in the Democratic Party really believes Vance fucked a couch and we're just trolling him, whereas if someone lied about Tim Walz fucking a couch half of the Republican congressional delegation would be demanding a DOJ investigation into the matter
Walz referencing a false story about Vance. “See what I did there?”
Some Republicans have been frustrated more media isn’t smacking down this kind of stuff, charging that it would be panned as disinformation if it were an attack on the left.