For those who sulk, and not vote. PLEASE, submit an empty ballot. If you all did that a message would be sent. This is a simple fact and blank ballots are counted. voting is not a right, voting is a responsibility. Not voting does nothing, other than prove, to yourself (and others when you brag on it), that you are not responsible, don't give a damn, and, certainly, part of the problem.
That happened in Michigan. It doesn't appear that the DNC got the message.
Politics works like this:
You have to get more votes to get elected. If you get less votes you lose. In order to win again you have to find a way to appeal to more voters so you can get more votes again.
Hectoring people, saying your better than the 'other side', and outright putting your thumb on the scales to rig the primary is not coming up with better appeals for voters to turn out. It's an admission that you have no ideas to lead with but want to maintain your good thing you got going at the expense of election victories.
Addressing peoples material concerns with proposals that have popular support does. It's been proven here in the past and abroad in the present.