Don’t rain on the parade. These schmucks would have voted with Obo regardless. Bayh knew he would lose and didn’t want the humiliation. He can always ride to the rescue during a more socialistic election year.
Or he can take Obambi on from the right in 2012, as Zero's political collapse has only just begun. Bayh has always fashioned himself as a "centrist", you know, and politicians like to plan ahead.