Obama promised too much during campaign, he enjoyed majority in both Senate and Congress to threw some billions and billions in a hurry to bailout banking and auto industry, with not much string attached. He and Whitehouse strategists might have enjoyed some quick short-term "victories" too early and forgot how to get some friends to back him up during smooth sailing.
Evan Bayh is a nice guy politician I used to remember back in Indiana, he and a few others perhaps have their own ideaology that Obama should have recognized earlier and try to have them on his side. Instead, Obama/Whitehouse had been pushing some decisions through majority unidirectionally, failed to respect Democrats colleagues' ideas and the basis. The missed judgement on both Obama/Whitehouse as well as Democrats leaders on Massachusetts' senator race made everyone point finger at everyone inside Democrats. A few good intent still need friends to ride along, it would otherwise backfire to become not so great ideas.