All you have to do to defeat that is to fucking vote.
And in places where the party's fuckery succeeds, you'll pretend that the primaries are fair because you like the results.
Yeah, there was talk about them rigging the 2016 primary for Clinton with the superdelegates if Bernie was ahead, but it never reached that point because Clinton secured the nomination before the convention.
The party successfully argued in court that it could decide the nominee in a smoke filled room without the input of the voters if it wanted. Then it did just that in 2024. And you pretend it was fair because a genocide candidate was nominated.