In a race where Clinton seemed to have every advantage, why has Barack Obama now won eight primaries and caucuses in a row? If you look at the rhythm of the campaign, this is the first point where most of America's voters have a chance to consider him as a candidate with a serious chance of victory, and to genuinely engage his message. Democrats passionately want a candidate they can believe in, but also one who can win--and reverse the Republican disasters. As the presumed nominee, Clinton did everything she could to play on this, proclaiming herself as tough, experienced, and capable of taking everything the Republicans could throw at her. She lined up massive insider support, including commitments from 154 superdelegates (versus 50 for Obama) before a single vote was cast.