He's a drip of a person. There is no enthusiam in the guy (believe it or not, Lieberman was the exciting member of his team. That says a lot).
He out-and-out lied and/or flip-flopped about a number of things before and during his own campaign (remember...he invented the Internet)
He was not the brightest bulb in the package, as heard in this this audio clip.
Plenty of people understand that there are more than 2 parties. If there weren't people that understood that, Bush 41 would have won a second term. Enough voters were taken from Bush by Perot and his Reform party that Clinton won.