You don't think that turned off the Dems, do you? Nah. The only reason they did not nominate Dean is that they thought he couldn't win. If the YEEEEEEEEEEEEEAAAAAAAAAAHHHHHHHHHHH! had been saleable to the public, they would have gone with him.
Hillary can't get close to 50% of the popular vote, but she can win the way Bill did in 1992, if a third-party candidate draws off enough votes from the Republican nominee.
Yes, it was such a negativity that the avg. middle-of-the-road Dem (NOT the far-lefties) was scared off. Dean came off like a loony. Thank goodness it happened sooner rather than later.