Bump Part II

What sort of Bump should Barack get from the convention? And should it be equaled by McCain after the GOP convention? Newsweek gets answers on how to view the stagnant polls from Tom Holbrook, professor of political science at the University of Wisconsin-Milwaukee and author of "Do Campaigns Matter?" Here are some highlights.

So you'd say that McCain is overperforming, given the climate?
Yes, I'd say so. Although not wildly so.The other thing that seems to matter here is that the first convention seems to get a bigger bump than the second. Not always, and it's not always a huge difference. But you compound that with the fact that Obama is running a bit behind where he should and I think it's safe to say that he's going to get a bigger bump than McCain.

Any predictions?
McCain could get a nice four or five point bump. If he does, I would expect Obama to end up with a six-to-eight-point bump. It's a little hard to tell right now without more pre-convention data. But I think something in that range wouldn't be unexpected.

Should the Obama folks be concerned about conflict with Clinton supporters at the convention? Could that diminish the 'bump'?
Sure, what goes on at the convention probably matters as well. There are times when the conventions are a mess, and that really ends up hurting the convening party. Take the Democrats in 1968 and 1972, for example. In 1972, George McGovern came out of the convention running two points worse than he was running before it. Most people attribute that to the fact that the convention was a mess, with McGovern delivering his acceptance speech in the middle of the night. That said, I don't think there's going to be much real conflict in Denver. It'll probably look more like 1988, when there was the whole argument between Michael Dukakis and Jesse Jackson--would Jackson speak or not? Despite the clash, Dukakis got a nice bump--just about seven percentage points--and was vaulted into the lead.

This year we have this unique situation where the conventions are separated by a weekend, as opposed to a full week or more. They're also relatively late in the season. How will this year's weird schedule affect things?
In my own research, I've found that the earlier in the summer the conventions take place, the bigger the bumps will be. I think in part because people are less settled on whom they're going to vote for and more open to persuasion. But the thing I'm most concerned about is the closeness of the two conventions. I think since we've have modern polling the closest two conventions have ever been is a week apart--Clinton and Dole were a week apart.

There are two possibilities here, and both these things could happen. The first one is that the Democratic Convention ends on Thursday, McCain will undoubtedly announce his vice-presidential choice on Friday and that will blunt any post-convention glow that usually translates into a bit more of a bump for Obama. The other possibility is that the convention hubbub is really getting started now, and Obama is going to announce his pick by Friday. So he's got these extra few days of pre-convention run-up publicity. Now, McCain's not going to have that. He won't the floor, so to speak, until next Friday. So the compressed schedule could also blunt McCain's ability to generate a large bump. It's a wrinkle that will probably have some effect. It might affect them both, or it might have a stronger effect on one than the other.