Based on the precision of Obama's campaign machine and its relatively drama-free ride albeit with the few standard bumps (e.g. Rev Wright or the "bitter" remarks), it appears, just on general principle that Obama wants a vice-president who will provide support and consultation with room for dissent but without the potential wild ups and downs of choosing Hillary Clinton. Let's face it, if you choose Hillary, then you're bringing Bill also in large measure. It will be a co-vice-presidency which was not talked much about in the Democratic primaries because Obama did not want to "go negative" but the Republican infrastructure will not hesitate in tooling up and pointing that out. In fact, nothing will get the juices flowing from what appears to be a lethargic Republican constituency than having not one but two Clintons trying to make a return trip, although a slanted one to 1600 Pennsylvania Avenue. Despite Hillary's repeated proclamations during the primary, "The public has a long track record of me and I can handle all of my own baggage", can be rebutted by the fact that most of her baggage is attached to and, at times, covered up by the former President Bill Clinton. If the media continues to go down this road of "guilt by association", then there will be plenty of questions which reprise past hits like Monica Lewinsky, Travelgate, Whitewater, questionable pardons, financing of a particular Presidential library, etc. to go around that may stunt any attempts of Obama trying to get America to get acquainted with his biography and message. The Clinton brand has a lot of upside but it brings past, present and very likely future histrionics that Obama has shown to veer away from.