Nate Silver makes his case:
Until she runs for office again...Palin's role is basically that of a celebrity on her own behalf, and a rabble-rouser on behalf of the GOP. Although each of those things can occupy a goodly amount of one’s time, the media is likely to tire of Palin if she’s not actually making news, and Palin herself may grow tired of not being the center of attention. Moreover, there’s not any evidence that laying low seems to help Palin’s standing with the public; on the contrary, her numbers seemed to have have declined a lot during the past several months, a period during which (until recently) she was not making much news.
The reason I suspect this may be the case is because Palin’s popularity seems to stem not from any particular attributes that she possesses as a candidate, but rather from the reactions that she seems to induce from other people. Only by being in the spotlight can Palin induce liberal pundits to say rude things about her, fellow candidates to behave awkwardly around her, etc. Only in this way can she be the martyr and the underdog, qualities that conceal some of her potential inadequacies.
I get the sense from the beginning of this tour that Palin may consciously want this and intend this, but is unconsciously seeking her own self-destruction. Her actions, as always, are not strategic. They are a function of emotion, paranoia, delusions of reality and some kind of professional death-wish. The question is simply how long she can continue before this whole thing implodes.
But then I've thought she was on the verge of self-destruction from Day One. I didn't think she'd be on the ticket by election day, remember. So what do I know?