non-mainstream candidate. Bernie is hanging on so long this time around for that reason IMO. He does seem to ahve that "outsider" mantle in spite of being a career inside the beltway guy. Non-mainstream is an apt description though - I can't think of another self-described socialist in my lifetime who has mounted this strong a challenge to one of the major party tickets.

With Trump, it is pure outsider appeal.

On on both sides, they have benefited in the primaries by very, very weak fields. Hillary is not great at running for office. The campaign trail is not her friend, and certainly not enough to insulate her from her baggage. And the repub field was terrible - each candidate fatally flawed for different reasons.

In a different time, very possible neither outsider would do nearly this well, even with their flawed competitors. And in this cycle, stronger mainstream candidates might still have beaten the "outsiders" as had been initially predicted.