ZOGBY POLL: “Brash McCain pick of AK Gov. Palin neutralizes historic Obama speech, stunts the Dems’ convention bounce . . . The latest nationwide survey, begun Friday afternoon after the McCain announcement of Palin as running mate and completed mid-afternoon today, shows McCain/Palin at 47%, compared to 45% support for Obama/Biden. In other words, the race is a dead heat.” If other polls bear this out, that’s big news. But this is only one quickie poll, so stay tuned. This USA Today/ Gallup poll doesn’t look as strong, though it’s of voter reactions to the pick, not a horserace question. But 23% of those polled had never heard of Joe Biden? I don’t know if that undercuts the poll, or just indicates that a lot of people just don’t pay attention to politics.

UPDATE: Hmm. This Gallup horserace poll shows Obama retaining his lead. Same at Rasmussen. So either Zogby’s found something everyone else has missed, or it’s a bad poll.

ANOTHER UPDATE: Reader Jon Aaron writes:

The Gallup and Rasmussen polls are daily trackers, which average the results over a 3-day period. So they mostly don’t reflect the impact of the Palin pick yet, and won’t completely reflect it until Monday or Tuesday. The Zogby poll was conducted entirely after the Palin pick. Zogby polls actually aren’t very reliable, but in this case there’s no discrepancy with Gallup and Rasmussen.

That makes sense. And looking back at the links, the Gallup poll was Wed. – Friday, while the Rasmussen was Tues.-Thursday. So neither really reflects the Palin shift yet. Will Zogby turn out to be right, or not? Stay tuned, I guess.