One of many nutshells...

of why I like Obama. This, from Matthew Yglesias, hits it right on the head, I think:

And that's one of the things Obama has that Hillary Clinton doesn't. If instead of Clinton or Obama, I were the one sitting in the White House, and I had some kind of appealing-but-controversial initiative I wanted to propose and for some reason I had to pick a Senator to be the "public face" of the initiative I'd pick Obama in a heartbeat. He's the kind of person whose support for an idea makes the idea seem more compelling than it otherwise would have. You can imagine him getting people interested in things that didn't previously interest them, or convincing people that steps they used to think were too risky are, in fact, necessary. Clinton, like lots of perfectly admirable Senators from Carl Levin to Jim Jeffords and beyond, doesn't have that extra bit. It's the difference between a person who has to change his policies to become more popular, and a person who makes policies more popular by espousing them. Obviously, that's a quality that exists on a continuum, but Obama seems to me to be much further toward the "makes more popular by espousing" side of the spectrum.