Before all these post-convention polls came out, I was on record as saying:

It’s not the bounce from the convention that’s important (and certainly not its exact size, which I suspect will be rather modest), but rather the extent to which Kerry has set himself up for a successful fall campaign.

I stand by that statement. The chief importance of the Democratic convention was that it could—and did—make a substantial contribution toward setting Kerry up for a successful fall campaign. In that sense, Kerry received a significant “bounce” from the convention, as all available polling data agree.

As for the traditional trial heat bounce, it does appear to be true that, just as I suspected, Kerry received only a modest bounce from the convention—but determining just how modest that modest bounce was has turned out to be very tricky indeed.

In previous posts, I discussed the Newsweek and the rather strange Friday-Saturday Gallup results, which showed Kerry tanking on Saturday night, thereby effectively eliminating his trial heat bounce. The situation was not cleared up when Gallup went back into the field for a third night (Sunday night), apparently to check their data. The Sunday results are fairly similar to the Saturday results and therefore reduce Kerry’s bounce even further. For example, the Kerry–Bush RV horse race is now tied at 48 percent to 48 percent, rather than a 50 percent to 47 percent Kerry lead. However, the various gains detailed above for Kerry on issues, candidate characteristics, and so on remain, even if slightly diminished by the third night’s data.

The next poll to consider is the CBS News/New York Times survey. CBS News finds Kerry–Edwards with a solid six-point lead among RVs (49 percent to 43 percent), including a seventeen-point lead among independents. However, this is only a slightly better lead than they had in CBS News’ July 11–15 poll (49 percent to 44 percent). But, again, this latter poll is still a bit too early to use to serve as a good comparison point for measuring the horse race bounce.

Otherwise, the poll is full of results that are quite favorable for Kerry. Bush’s approval/disapproval is 44 percent/49 percent (37 percent/51 percent among independents). His rating on the economy is just 39 percent/54 percent (30 percent/59 percent among independents), even worse than two weeks before, when it was 42 percent/51 percent. And his rating on Iraq is even lower than his economic rating, at 38 percent/55 percent.

Right direction/wrong track has also fallen over the last two weeks and is now at an abysmal 36 percent/59 percent.

Moreover, voters believe Bush’s presidency has divided Americans (55 percent), rather than brought them together (31 percent). But they believe the opposite about a Kerry presidency: by 53 percent to 29 percent, they think he would bring Americans together.

They also believe, by 55 percent to 41 percent, that Bush does not have the same priorities for the country that they have, whereas, by 47 percent to 40 percent, they believe that Kerry does.

Kerry also has succeeded in convincing voters he has strong leadership qualities: 58 percent believe that about him, the exact same number as believe that about Bush.

Finally, Democrats have made substantial progress in convincing voters that they have a clear plan for the country. Two weeks ago, by 51 percent to 36 percent, voters said that they didn’t have such a plan; now by 44 percent to 40 percent, voters say that the Democrats do.

The final poll to consider is the ABC News/Washington Post (WP) poll, which, at least in terms of timing, is the best-positioned to measure the convention bounce. Their pre-convention poll was on July 22–25, the period exactly preceding the convention, and their post-convention poll was July 30–August 1, the period exactly after the convention.

Perhaps coincidentally, it’s also the only the poll that finds much evidence of a trial heat bounce. Before the convention, Bush led Kerry in this poll, 49 percent to 48 percent (an unusually pro-Bush result, though they were the only poll in the field at the time); after the convention, Kerry leads Bush, 52 percent to 45 percent. That’s a four-point bounce in terms of support level for Kerry and an eight-point bounce in terms of margin.

This bounce is modest by historical standards but is certainly more substantial than that suggested by other polls, particularly the rather peculiar Gallup poll. And note especially the failure of the Gallup poll to detect a Kerry lead at all: the WP poll has Kerry ahead by seven points and CBS News by six points on the exact same survey dates; the Newsweek poll has earlier survey dates and has Kerry ahead by eight points. The Gallup poll is truly an outlier among these major polls.

The WP poll also shows a lot of bounce for Kerry on a variety of important issues and characteristics. His favorables go up from 48 percent/39 percent pre-convention to 51 percent/32 percent post-convention. His advantage on the economy goes from –1 to +11; on Iraq, from –12 to +2; on education, from +1 to +13; on the campaign against terrorism, from –18 to –3; on health care, from +3 to +19; and on taxes, from –6 to +6.

On candidate characteristics, he also posts strong gains: on honest and trustworthy, he goes from –6 to +6; on understands the problems of people like you, from +4 to +14; on strong leader, from –19 to –6; on making the country safer and more secure, from –16 to –3; on shares your values, from –6 to +6; and on having a vision for the future, he bests Bush by thirteen points.

Kerry also is now considered more of an optimist; pre-convention, he was considered an optimist by 55 percent and a pessimist by 34 percent; now he is rated an optimist by 65 percent and a pessimist by 22 percent. That’s actually a better rating than Bush now gets on this question.

And here’s a particularly impressive result: by 52 percent to 44 percent, voters select Kerry over Bush as the one better qualified to be commander in chief of the U.S. military.

So, arguably, Kerry got a substantial bounce where he needed it most, but that improved image did not—perhaps could not—pay immediate and large dividends in terms of trial heat measures. After all, given that (a) Kerry was already doing well in trial heats for a challenger; (b) he’d already “spent” some of his bounce early by selecting Edwards as his running mate before the convention; and (c) this is already a highly polarized race with relatively few undecided voters, there was little room for Kerry to go up quickly in the trial heats. But the substantial gains on image and issues he made as a result of the convention put him in a good position to continue to build his lead over Bush as we move into the fall campaign.