As an example of James David Barber's presidential character framework, Nixon would likely be classified as a worst-case active-negative type e.g. he does a lot of damage to the country as he grapples with his personal demons.
However, my take on Obama is that he may be a passive-positive president in the manner of the compliant, hands-off, drifting but ever optimistic Reagan. This is opposed to active-positivist Franklin Roosevelt who remained upbeat and accomplished substantive and enduring results.
As Rosenberg asks whether Obama is just about a change in tone that taps into underlying existing sentiment or about something more fundamental, he has this interesting aworks-relevant paragraph about the scope of what Obama probably does not represent:
But it's not as Monty Python would have it, "something completely different." It's not Frank Zappa changing key and time signature at the same time. And it's certainly not Charles Ives, playing in two different keys at once, or Harry Partch, playing in just intonation, with 17 notes to the octave. So if Obama hasn't given a major speech on GLBT issues-as some of you are surely already protesting--it's precisely because there is no such latent change on GLBT issues overall, even though there certainly is such a change with regard to their service in the military.