Get it straight.
Bernie has every right to run in California and through the convention. The Democratic political establishment has tilted to Hillary from the beginning. Hillary has appropriately heard the message, especially about income inequality, and moved to the left. Hillary has more votes and more delegates than Bernie.
There's no need to paper over the disputes. Bernie is leading a movement, not just a campaign. He has taken a corrupted election system and used it honestly to move a progressive agenda, and more power to him. His people feel the outcomes deeply. But there is so much at stake, and a history of lasting splits after Democratic primaries, that it's time for both campaigns to focus on what matters.
When these things go wrong, the consequences are, well, Apocalyptic. In 1968 I was part of the McCarthy anti-war effort. After tumultuous and horrific events, Humphrey won the nomination. The movement never quite accepted the significance of the general election and we ended up, by a whisker, with Nixon. Nixon. America would have been vastly better off with Humphrey.
In 2000, Gore was the nominee. Nader siphoned off enough progressive votes in enough states to throw the election to Bush. Bush. Iraq, Afghanistan and the Supreme Court. American would have been vastly better off with Gore.
We face the same fearsome outcome now. A percentage of Bernie-ites have announced they will never support Hillary. Hillary, at her worst, is competent, decent and reasonably progressive. No need to ignore the character and policy concerns. But there is no reasonable argument about the choice. Trump? Really?
Bernie understands and will, eventually, do the right thing. It would be smart for the Democratic leadership to bend over backwards to make it easier for him. But in the end this will be in the hands of a lot of decent, progressive people who have correctly fought for an end to income inequality, racial, gender and sexual orientation bias and more. There is no reasonable argument about the choice. In November, if Hillary is the nominee, with all her limitations and strengths, support for her is a moral imperative. The consequences of President Trump will make the Nixon and Bush years seem like a paradigm of stability and progress.
There is no reasonable argument for progressives to do anything but vote for Hillary.