It's only a 45% to 44% margin but that's something in the biggest "pink" state and Mason-Dixon is respected in southern states including Florida.
It may be a DNC or housegate bounce but the poll says the Biden pick was not influential (or hasn't had an effect yet).
The poll, of 625 likely voters, also showed that Obama’s selection of Delaware Sen. Joe Biden to be his running mate on the Democratic ticket is not having a large effect on Floridians. Only 14 percent said Biden made them more likely to vote for Obama, while 11 percent said it made them less likely.
sorry i can't reprint the entire poll as it's pdf but here's the link to the story (there's a link to the pdf complete poll in the story):
http://www.wesh.com/...
(is !! better than Breaking?)