OBAMA'S POLL DIP, WHICH IS SMALL AND SHOULD BE TEMPORARY
First, the numbers:
... Gallup had the candidates tied yesterday at 45% each, today McCain edged ahead to a two point lead over Obama 46-44.
Rasmussen showed an even bigger overnight move. Yesterday Obama led McCain by 3 points, 48-45, today he shows the race tied at 46.
(Rasmussen link here.)
No surprise that Biden didn't provide a bounce -- he's never been a real political star, and his pick wasn't meant to win instant acclaim from the general public. Biden's value to the campaign, if everything works out right, will be for all the reasons you've read everywhere: long resume, foreign policy experience, pugnaciousness, Catholicism, et cetera. He'll help the ticket as people see him in action.
This is offset by the fact that a fair number of people wanted Hillary Clinton on the ticket and hadn't quite grasped (or come to terms with the fact) that that wasn't going to happen. However, there are clearly fewer than 18 million such people, or Obama would have plummeted in the polls.
Now here's why the dip ought to be temporary (and I stress "ought to"): the polls you're seeing now are the few polls taken between the running-mate announcement and the Clintons' convention speeches. If the Clintons give the speeches the party needs them to give -- gracious to Obama, tough on McCain and the GOP -- then a lot of Hillary supporters (especially the ones who aren't paying attention to every twist and turn in the race, who are likely to be the same people who thought she had a chance to be #2) will accept the passing of the torch. That's a big if, but I take hope from Hillary's "I do not approve that message" remark.
So get back to me after the convention, and don't panic about today's polls (based on interviews conducted Saturday through Monday) -- or even tomorrow's (conducted Sunday through today). It's going to tak a few days, if the convention goes well.