The policy defines the party: the party does not define the policy. "Any economic unit can emit money. The serious problem is to get it accepted" Hyman Minsky
French technocrats in the middle of the 20th century, prodded by a strong communist party and backed by a fairly paternalistic rightwing, did a pretty good job of working for the general good, notably by building high quality infrastructure for all.
The tools they have used, and exported to notably the European Commission, still work, but they are now used for less broad objectives.
So you need (1) elite technocrats and (2) the proper goals for them.
Ultimately, you get to the question of how to reward elite technocrats. A recognition of their eliteness goes a long way, but this is undermined in a world where money is the ultimate arbiter of who is really elite, become making money does not necessarily require competence... or at least not the right kind of competences, that build rather than destroy or pilfer. Wind power