Because I think that a majority of people (Democrats, Republicans and otherwise) got intellectually lazy a long time ago and just assumed that she was going to be the nominee without even bothering to consider that there might be other people out there. I think that that assumption might have created a self-fulfilling prophecy. I don't buy that she's the best shot that Democrats have. I think that a left-populist that ran an anti-Wall Street campaign would in some ways be more popular. The problem is that there is no real liberal equivalent of the Tea Party to challenge her and be uncompromising from the left.
Also very prophetic.
