Ross takes a stab at it:
Palin’s fall, I suspect, has been driven primarily by negative press reports on her Alaska career (with the anti-Palin notebook dumps in the Times and the Post leading the way), ongoing coverage of the still-simmering Troopergate scandal – and especially by her widely-watched, none-too-impressive interview with Charlie Gibson, which aired the day her slide in the polls began. The Obama campaign, meanwhile, has busied itself going after McCain – for lying in his ads, for being out of touch on the economy, etc. etc. – and avoiding the "she’s just a small-town mayor" attacks that they trotted out immediately after the Palin pick was announced. Or at least that’s been my impression – it’s possible that there’s been a barrage of anti-Palin fire from the Obama camp that I’ve missed, but by and large it seems like they’ve been doing a decent job of just getting out of the way, and leaving it to the media (and Palin herself) to undo her initial spike in popularity.
Yglesias differs. I don’t think we have yet seen the real Palin crash. But I’m a patient man.
The Dish 