I generally agree with Doug's point here. But the broader social vision can work both ways and can come from below as well. I previously mentioned Winn's book Weavers of Revolution on Chile. According to his telling, Chilean workers (some at least) were pushing for a more thorough and rapid transformation towards socialism with factory expropriations. And Allende was trying to put the brakes on or at least slow down the process. In part because he feared it would antagonize the ruling class too much and too soon and provoke what eventually happened anyway.
Anyway, the socialism from below of factory seizures certainly needs to be supplemented by a larger more encompassing movement that seeks state power in my humble opinion.
Sheldon