John Kerry would definitely be the "lightning-rod" selection. He has made an entire career out of making bad decisions about foreign policy, and would likely be a disastrous choice for Secretary of State. He is, however, second only to Obama himself in his liberalism, and rewarding Kerry for a lifetime of service to Communist ideology by awarding him the highest office in the Cabinet might be too attractive for Obama to resist.
The most likely choice, in my opinion, and probably a decent one, given his qualifications, experience, and natural talents, is Bill Richardson. Richardson can at least be tolerated, and may actually turn out to do a pretty good job. Fair warning, though, Governor: follow the Constitution, or prepare to experience the wrath of MOCKBADOC.
MOCKBADOC Predicts that the Hope and Change Secretary of State will be New Mexico Governor Bill Richardson.