For instance, Marx was big on universal suffrage, not because he was in favor of it as an endpoint but he thought it was the kind of demand that developed the consciousness of the working class movement, because it was feasible and achieving it would change political conditions such that new demands could be made...

I think a good modern analog to this would be demanding electoral reform (particularly, proportional representation and ranked choice voting). We probably will not achieve it, but we can still get society to start talking about proportional representation, and we'll eventually get people to realize that their political interests have more to do with their economic situation as a worker (as well as their cultural preferences, if we're being honest) than with which town they happen to live in, and that basing our system of political representation on arbitrarily drawn geographical districts is stupid. We can get people to become more disillusioned with the political representation system, and if we do it right, that will lead to them being more disillusioned with capitalism as well.