Maddow vs. Frum vs. Maverick

He's against "whipping Republicans and conservatives into a fury," but also manages to throw a tu quoque at his hostess:

Note Frum's use of "my party." That sort of proprietary phrase always bothers me for some reason -- I don't like it when conservatives speak of the Republican Party as "we" -- but there's something else going on here. It's his party, not your party? By what right?