Sanders to run as a Democrat -- but not accept nomination (2018 Senate)

[Jim Lane]

440. Nothing "blocked" here

What you describe as "the party establishment chooses the candidate/nominee before the primary" is actually party leaders or entities making an endorsement. I don't recall your previously recoiling in horror from that scenario. Apparently party endorsement in favor of Bernie Sanders is a threat to democracy, while party endorsement of someone running against Bernie Sanders is noble and virtuous.

You despise Bernie Sanders, fine, that's your right. But, as Sanders himself proved, a candidate who has little support from party leaders can still run in a primary against their choice.

In 2012, Sanders had no opposition in the Democratic primary. This year, because of all the people who are fixated on refighting 2016 and wreaking vengeance on him for opposing their chosen candidate, the primary will probably be contested. IIRC two Vermonters have already announced. A Clinton staffer has announced plans to move to Vermont and run, but I suspect that he was just making some kind of silly joke. Whatever, Bernie will be on the ballot, other candidate(s) will be on the ballot, and the voters will decide. As you say, it's not very complicated.