Trump won because he was willing to say loudly what his supporters believed deeply; because, in his disdain for what politicians are supposed to be and do, he exuded authenticity; because he was hated by the people his base found hateful; because he had an opponent who, in the minds of his supporters, epitomized corruption and self-dealing; and because he offered radical cures for a country he diagnosed as desperately ill. Despite being the oldest man ever elected president, he seemed (to his voters) fresh, true, bold, and sorely needed.
So it is, and would be, with Sanders. Depth of conviction? Check. Contempt for conventional norms? Check. Opposed by all the right people? Check. Running against a “crooked” opponent? Check. Commitment to drastic change? Check. Like Trump, too, he isn’t so much campaigning for office as he is leading a movement. People who join movements aren’t persuaded. They’re converted. Their depth of belief is motivating and infectious.