Already covered.
The $64,000 question: If the freaks and/or Al Qeada make a mess out of the Republican Convention, will the US "do a Spain" or will the American people get pissed off at the bad guys and Bush's popularity goes up a couple notches as a consequence. It's hard to tell. If Bush's campaign managers are sharp, they're asking this same question right now.
If Al Qaeda do anything during the GOP affair it will boost Bush. Since they didn't do it to the Democrats the appearance would be (by default) that Al Qaeda is supporting Democratic candidates. They would have had to do it to both to be successful politically against Bush. But doing it to both would frighten Democrats enough into a level of responsibility they can only rise to after events like 9-11. So attacking either convention is a lose-lose proposition. It's general terror attacks that are a greater concern - and actually one can bet that the day they will NOT occur is on the day of the GOP convention for the aforementioned reasons.
Al Qaeda isn't that swift though, so if they do attack the GOP convention or on the day of the convention - they would play into Bush's hands. I think the top Al Qaeda operatives are savvy enough to realize that they wont be able to pull a "Spain" here.