There's an new broadcast commentator in town. Get ready for the Republican voice and face of Meghan McCain on ... MSNBC. "I'm very excited," said McCain, 28, in her broadcast staff debut yesterday as she weighed in on the GOP field. "I didn’t know it was going to be announced, but I am excited to join the MSNBC family." Gawker was less enthusiastic about McCain, who cut her political-analyst teeth on her own blog and via the Daily Beast. Gawker grumbled that MSNBC is boosting its "stable of dolts spawned by famous figures by a factor of two" after its hiring last year of political reporter Tim Russert's 25-year-old son, Luke.