I’m not entirely sold on the “branding” excuse.
Grant it that Capitol Hill is lost, but that’s just one institution. And, Republicans suck at messaging only because most of them have no core. As a first principle they cede the field, to the side that does have a message. The Left.
It’s more about half of our country has been “educated”, from K-12, to be cheerfully deprived of any “education”. We ceded that field ages ago. Never mind the University level. That’s been ceded in double time.