Wouldn't vote if too cocky about victory? Wouldn't vote if too worried about defeat? Really?
Maybe it works that way in the general populace with some people, but I doubt that many DUers would skip voting regardless of their optimism or pessimism.
If Obama wins (and I'm modestly confident he will) I want to be a part of that, no matter what.
If this election goes to hell and Romney wins, I definitely want to be able to proclaim "I voted for Obama! The mess Romney makes isn't my fault!"
So why all the worrying that some bit of positive news is going to make people "too cocky", as if that would stop us from voting, and the contradictory concern we'll be demoralized at not vote when we hear bad news?
My desire to get out and vote will never be affected by optimism or pessimism. About the only thing I do that might change, and only in an election situation which seems very far from being close, in either a positive or negative way, is that I might be less motivated to give as much of my money or time to either a seeming "sure thing" or an apparent "lost cause".
I doubt I'm going to experience many elections in my life, if any, that feel so very assured or so very doomed.