If we chose party candidates democratically, where we all had an opportunity to vote for them, Bernie Sanders would win easily (see here). But the party system doesn't work that way, especially for the Democrats. From the article: Sanders just swept through the West, winning five of six contests by
stunning margins. In addition, he isn’t just a candidate — he’s a cause.
Sanders seeks to build a movement that can make the political
revolution needed to transform the country, not simply win the White
House....He’s already won 15 primaries and caucuses, and lost four more by the barest whisker. And he keeps rising.For the first time, the most recent Bloomberg poll shows him edging ahead of Clinton
among registered Democratic voters. Other national polls consistently
show her once forbidding lead continuing to narrow. Sanders draws large
and mostly enthusiastic crowds and continues to rouse young people
across the country. His supporters are eager to fuel his campaign. He outraised Clinton dramatically
in February — $43 million to $30 million, as his 2 million small donors
contributed more than her deep-pocket investors. In fact, more than 70
percent of Clinton’s donations have come from large donors, who are maxing out in increasing numbers.
Why won't he win handily? All of the "superdelegates" are pledged to Clinton. What are super delegates? Delegates who aren't awarded by primaries. (see here) But he, along with Trump for the Republicans, is showing that big money doesn't have to drive every political outcome.