When someone "goes birther", that means they have given up their last thread attaching themselves to reality, and flinging themselves into full-on wingnut mode. You can usually tell when someone has gone birther because they literally start spouting nonsense about how Obama's birth certificate isn't real, though many think they're clever and employ euphemism to give themselves plausible deniability. Until yesterday, most of the sane world would note that Sarah Palin wasn't a full-blown lunatic because she still hadn't gone birther. Well, that day has now come.
As you will note, Palin maintained plausible deniability, suggesting that it should be looked into, without committing to a stance. But looking into it is committing to a stance, because it's been exhaustively examined, and proven beyond a shadow of a doubt that Obama was born in a genuine American state. Refusing to accept this is being a birther. When a question has been answered so fully, way beyond the satisfaction of all non-nutty people, then to say there is a question at all is to side with the nuts.
That Palin attempted to be dodgy does bring up a question, however: how much of a true believer is she? I detected a note of genuine impatience in her voice. Perhaps as a denizen of Alaska, it occurs to her that she's as much a citizen "in question" as Obama is. (Which is to say not at all, but believe me, liberals should not refrain from pointing this out when wingnuts go birther on you.) Perhaps she knows it's bullshit, but she also knows that she's the Queen of Bullshit, and so she has to represent on this issue. Certainly, she's trying to find a way to make her base of birthers happy while not excluding herself from the mainstream. Good luck with that---like creationists, you either are or aren't a birther.
The other thing that struck me about her interview was her contention that she didn't go after Obama enough during the election, and namely, that avoiding the birther thing was a mistake. I suppose she could have gone completely off the deep end during the campaign, and certainly it seems she wanted to but was held back by McCain, but good god, who in their right mind thinks she wasn't enough on the attack? She accused Obama, through implication, of being a terrorist. She did so in a way that maximized the anti-Muslim insinuation, even though neither Barack Obama nor Bill Ayers (who is the excuse for this rumor-mongering) is Muslim, making the whole thing not only racist but incoherent. She went out of her way to imply that anyone who was not white or lived in a city was not a Real American. She red-baited Obama. She did everything but tell jokes about his mom. Her entire campaign strategy was to attack Obama. I fail to see how she could have done more, honestly. There aren't enough hours in the day.