The Clintons best chance at this point is to angle for a Mccain victory and then a Hillary in 2012 comeback.
I believe that it was Clinton that turned down Obama for this reason. They do not want Obama elected for that would ruin their opportunity in 2012. The Obama people had to know what Hillary would bring to them if selected as the V.P. candidate. The Clintons are purposely undermining the Obama campaign at the convention to help push him off the edge.
Apparently you missed the insult that Obama laid on Hillary last week, he said that he had never considered her for VP, hadn't vetted her and never gave having her as VP a thought. That really ticked off the PUMAs as you might guess. So, no, Hillary didn't turn Obama down, she would have probably but she was never given the chance.