I’ll wager Mitt, since Mitt toured the Shot Show with NRA brass, and NRA defends his permanent assault weapons ban in MA (It did not make the ban permanent! The ban was already permanent! Mitt successfully negotiated the deal so that the License to Own a Gun was to be wallet sized, and when the cops confiscate your guns, you MUST now get a receipt...)
They have already endorsed an anti-gun candidate (a Governor I think).