If Bush had 28% and Kerry had 67% I would say that Bush is going to lose as well.
Even if they said that the day after he entered the race?
A defeatist is not just somebody who believes he's going to lose, a defeatist is somebody who because he believes he's going to lose, concludes he should bother fighting at all.
You think the Spartans at Thermopylae thought the 300 of them had any chance of defeating the half million Persians? But what would have happened to Western Civilization had they laid down their spears and not fought.