Some signs of a unity bounce

It's very early, but both of the national tracking polls are showing results that are consistent with the notion of a "unity bounce" for Barack Obama.

Rasmussen:

The Rasmussen Reports daily Presidential Tracking Poll for Friday shows what may be the beginning of a bounce for Barack Obama. Obama now attracts 45% of the vote while John McCain earns 40%. That five-point lead for Obama is up from a two-point advantage over the past couple of days. Before that, for much of last week, McCain had enjoyed a slight edge.

Gallup:

The latest results include two nights of interviewing since Obama declared victory over Hillary Clinton on Tuesday night in the Democratic delegate contest. Although Wednesday night's interviewing showed no immediate bounce in national support for Obama versus McCain, Thursday night's results were quite favorable to Obama. It will be important to see if Obama can maintain this support over the coming days.

We don't know that this is triggered by Clinton-supporting Democrats coming back into the fold. It could just have easily be independent voters who are caught up in the excitement of the past couple days, or were turned off by John McCain's awful speech. Both of those phenomena are likely to be more transient than a true unity bounce. Naturally, it could also just be statistical noise.

But as someone who has been pitching the notion of a unity bounce for a long time, my expectation is that some of this is going to stick in the near-to-medium terms.

There's also a chance -- I wouldn't call it probable, but it's distinctly possible -- that Obama is going to gain several points over the next couple of weeks and essentially never give them back. When I saw Mitt Romney on Morning Joe the other day and he was really lowballing expectations for McCain (e.g. "it's amazing that we're tied"), I got the impression that this is something the Republicans stay up late worrying about.