Effect

Matthew Yglesias:

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.