1) Polls have tremendous value to campaigns. They are used to measure response to message and to determine where to campaign. They are not, by any stretch of the imagination, useless. Millions are paid for them.
2) Obama’s team has a compulsion to get him perpetual exposure. They have come to believe that his appearance and demeanor are everything. They are taking an enormous risk in that the public is going to become immunized and desensitized and if he goes to Denver and gives his speech and the poll numbers don’t bounce, THAT will be the story — how for the first time ever a Democrat nominee did not get a bounce out of his own convention, especially when McCain does get one.
3) They have seen the recent Colorado numbers showing a McCain lead. They know Ohio is showing a huge McCain lead. They are facing a situation where they MUST find some electoral votes and that is what Kaine in Virginia is about. They can flip Iowa and New Mexico both, but that’s not enough EVs flipped to win if McCain holds all the rest of Bush’s 2004 states.
4) Virginia polls will be interesting, because that is where the “Wilder Effect” was invented.
Honestly, I think that the big story out of Denver will be how they switched to a larger venue, and were unable to fill it. A 20,000 seat venue that's filled to the brim and turning people away adds to the Obama "mystique". A 60,000 seat venue with 10 or 20K seats empty says "Why didn't this sell out?"
I could be wrong, might depend on how desperate the Dems are to put butts in the seats. Free concerts, Free Food, Free Money (want $20? Just be sitting in your seat when Obama speaks....) will be the name of the game at his "coronation".
We'll see. I think that story #2 might be the Dems that riot.