How come? Polls & numbers (whatever value they have this early on in the "general" cycle) state otherwise. In fact, it looks like Bernie has a much better chance at the moment than Hilary... Don't you think Trump would dominate 24/7 news cycle on digging up Hilary's old wounds? What does he have on Bernie? "He's a communist you're voting for a communist!"?
Interestingly enough, the polls say otherwise. [0] [1]
As the Politifact piece notes, (1) it's early in the campaign; (2) Bernie is much less well known than Hillary, and his perceived negatives might become more important in the general election; and (3) polls can always be wrong. Nonetheless, it doesn't seem to be correct to say he has far worse odds against Trump than she does.