If he loses the nomination, the Democrats won't win the presidency next year (unless somebody like Biden wins). They won't even have a fair shot:
But counting Edwards out would be a big mistake. Flying below the radar, the former vice-presidential candidate is pulling off a feat that Democratic consultants have long considered impossible: staking out the most progressive platform among the viable candidates while preserving an aura of electability. In head-to-head polling against the likes of Rudy Giuliani and Mitt Romney, Clinton and Obama have managed to post only modest leads. Edwards, by contrast, not only bests every Republican candidate in the race, he trounces them -- by an average of twelve points.