[@Tortoise]Probably helps that the vampires were originally just scientists and researchers who didn't like the Party too much. Imagine if the Party actually had some patience and they were the ones to get their hands on the Blood. 

Of course, the vampires aren't entirely blameless either. They've kept a lot of the repressive structures and institutions that the Party made, only softening them and making sure that people live comfortable lives so they don't ask questions. Propaganda is also widespread but more subtle, usually in the form of how enlightened technocracies are and the wisdom of age along with hamming up how terrible the Party and live under them was. Vampires also live in greater comfort than the living but that's totally just because they live longer and thus can gather more wealth and control zombies to do stuff for them and totally not because they have ways of siphoning off wealth like blood.