In his view of history, in his respect for tradition, in his skepticism that the world can be changed any way but very, very slowly, Obama is deeply conservative. There are moments when he sounds almost Burkean. He distrusts abstractions, generalizations, extrapolations, projections. It's not just that he thinks revolutions are unlikely: he values continuity and stability for their own sake, sometimes even more than he values change for the good.
And such a man, when he pushes for felt change, has more credibility and more of a chance to succeed. His candidacy is, to put it in Oakeshottian terms, an intimation to be pursued.