Really, who knows? The average bounce from a challenger's convention is 7 points; if you take out the outlier 1992 Clinton convention, it's 6 points. But this year there are fewer undecided voters and Kerry's already doing quite well in the polls, relative to average challenger performance, so it will be harder for him to post big gains.

But if you want a good summary of the things to think about as you listen to Kerry's speech tonight that may affect the bounce and, more importantly, the campaign in general as we move forward, you should definitely check out Frank Newport's Gallup analysis of the political context for Kerry's speech.

Newport makes a number of good points. I particularly liked his questioning of the alleged necessity for Kerry to focus heavily on assuring voters he'd be a strong leader in the fight against terrorism. Newport points out several reasons to be skeptical:

First, most recent polling shows that terrorism is in fact not the single most important issue for voters this year. Terrorism usually falls behind the economy, and in some polls, Iraq, when voters are asked to choose from a list of concerns.

Terrorism is not considered to be the most important problem facing the nation today. The top problems are the economy and Iraq.

More importantly, perhaps, is the fact that while Republicans place the greatest importance on terrorism as a campaign issue, Kerry's core Democrats and the vitally important independents do not. The latter groups are more interested in domestic issues such as the economy and healthcare.

So, Iraq, the economy and health care are all, arguably, deserving of more attention than the war on terror.

On Iraq, Newport has this to say on Kerry's handling of the issue:

....it is clear from the available poll data that Kerry has yet to take political advantage of this Bush vulnerability. For example, only 45% think that Bush has a clear plan or handling the situation in Iraq, but an even smaller 33% believe that Kerry has a clear plan for handling the situation there. Furthermore, when asked which of the two major candidates can do a better job handling Iraq, Bush edges Kerry by a 49% to 44% margin.

Thus, the data suggest that Kerry has yet to convince Americans that his approach to Iraq -- if elected -- would be that much better than Bush's.

Finally, Newport ticks off three reasons why the political payoff from emphasizing the economy could be high:

The public's rating of the economy's direction is significantly worse in states that are considered to be Democratic or battleground states than in states considered to be safe for the Republicans. In other words, the economy has a high probability of being of the most importance in precisely the states Kerry must win in order to become president.

As noted, independent voters are more likely than Republicans to say the economy is the top problem they will consider in their presidential vote.

There is evidence from data analysis from three key showdown states that voters' perceptions of the economy in their state is related to their propensity to vote for Kerry.

Is this guy right or what? Sure hope the Kerry campaign visits the Gallup website every once in a while.