Why was the '88 Dem field so weak?

[J. J.]

Kennedy had personal problems, Biden got tripped up on the plagiarism thing.  Hart, the initial front runner, was in a sex scandal.

You also had Jackson, who was the runner up.  To an extent, Gore was seen as a bit of a red neck.  Ed Koch's rhetoric against Jackson helped increase that:  http://en.wikipedia.org/wiki/Ed_Koch#Political_endorsements 

Gephardt was never more than regionally successful.