If Bernie ran as an Independent (the party he holds a Senate seat as), he'd still be in the race.

Maybe there are rules for getting in on debates, but I'd like to know how many people are relying strictly on debates/who he won over in those that he wouldn't win over with a simple commercial.

The party is at fault for not trusting him for two straight cycles...and he is at fault for trusting the party for two straight cycles.