I think Bayh is a respectable democrat. OF course, he's not Zell Miller or John Breaux (I'm suprised Breaux never endoresed Bush like Zell did). But he's a modern democrat's version of a moderate.
The only thing "respectable" about Bayh is that he is anti-PBA, but not much else (and I've heard some rumors regarding him that I won't repeat openly), but most 'Rats I've spoken to said there is NO WAY Bayh would get the Presidential nod (partly on the abortion issue, and others). You have to remember, the base of the party is SO radically left, their litmus test for candidates is 180 degrees away from ours, and they can't veer from it one iota. As for John Breaux, he's a mixed bag, but he's largely been a slick character who is very calculating at home (he was initially going to resign early to allow Chris John to be appointed to his seat, but decided against it for fear of a backlash). I think the most respectable Democrat in LA right now is New Orleans Mayor Ray Nagin. He really put his neck on the line endorsing now Rep-elect Bobby Jindal for the Governorship last year, and probably has ruined his chances for a 2nd term. He's the best Mayor the city has had in ages, if only because he has ETHICS.