You are correct, however there may not be a non-establishment democratic or republican candidate on the ballot for American voters once the nominations have taken place.
If Bernie doesn't get the nomination, I'll vote Trump. Not because I'm republican, not because I'm crazy, but because I refuse to waste my vote on a political robot.
As I allured to in the previous post, Trump may also not be nominated by the powers that be. Call me cynical, but the people nominated and presented to the voters, are preselected by the capitalist class.