But that implies that the members of the party are actually part of the proletarian class. This supposed class membership is purely idealist.
You are incorrectly defining class. This essence of class is: who controls the means of production, and who decides what to do with the surplus value created.
State administrators (uncharitably bureaucrats as you would call them) are not a class. They do not privately owns means of production, nor collect the surplus value of workers, deciding privately what to do with it. What to do with the surplus, and production decisions, are determined by decision making at the collective, political-level, not at the private level.















Wrong again. The working class is the owner of production, and elect and delegate managers dedicated to this task.
Name me a single grouping of any kind that doesn’t have managers, leaders, or organizers.