Not moving the goalposts. He’s not a member of the Democratic Party. Being from Vermont doesn’t preclude you from being a member. It’s asinine reasoning to say that Vermont is what prevented him from being a member of the party. Go do some research about why he hates the party.
The Democratic Party isn’t his party. And if he’s such a great visionary, organizer, and candidate, he should have coattails. If the platform was palatable to the majority of Americans, there should be more people like him running for higher office and winning.
Also, Trump and Bernie are two sides of the same populist coin. The only difference is Trump is actually a member of the party he ran with.
The Democratic Party “corruption” is a figment of your imagination. Also, the four primaries the Dems lost in were in districts that are overwhelmingly Republican in a way that a Dem running within 10 points is normally unimaginable. So the fact that they cut in is incredible.