http://www.cnn.com/TRANSCRIPTS/0401/25/le.00.html
BLITZER: And the decision you've made to drop out and not seek reelection was?
EDWARDS: Why?
BLITZER: Yes.
EDWARDS: Because I don't think you can run for president of the United States while you're holding onto the side of the swimming pool. I mean, you have to be very serious and totally committed. And no one can have any doubt.
When you ask a caucus-goer in Iowa to caucus for you or a voter in New Hampshire to vote for you for president, they can't be thinking, "Well, if this doesn't work, he's going to go do something else."