The best recent profile of Barack Obama appears in the New York Times, by James Traub, focusing on his foreign policy. It's long but worth reading the whole thing, especially for the pay-off discussion towards the end:
[T]he frustration of months of pedaling hard and getting nowhere began to show. [Obama] wanted to know what kind of experience Clinton supposedly had that he didn't, and what kind of crisis she was supposedly better suited to than he, and why "toughness" had become a stand-in for experience, and how Clinton could get credit for it when she failed to stand up to Bush on the Iraq vote.
