It's a much more complex question. For start, while Joe McCarthy himself is the greatest individual symbol of this whole period, there were many other crucial people and events in which he played no role. (For example, the Hiss affair, arguably the very central event of the whole era, had happened before McCarthy came to any national prominence.) Now, the whole "McCarthyist" reaction (a.k.a. the "Second Red Scare") did have some significant influence on things. After all, the U.S. back then still had some strong and functional institutions of democracy and federalism, and the Washington elites were in genuine fear of politicians who were riding on people's (quite reasonable) anger against the worst outrages of the New Deal regime. This clash was resolved with the complete defeat of these politicians, who were either destroyed and consigned to infamy, like McCarthy, or eventually lost their edge and got assimilated into the establishment, like Nixon. But the blow they delivered did have a significant influence in altering the course of events in a number of different ways. (By the way, Moldbug has written a very insightful analysis of McCarthyism as the last dying gasp of meaningful representative democracy in the U.S.) As for the U.S. prospering in the 1950s and 1960s despite all this, it's always futile to discuss historical counterfactuals. There are way too many confounding factors involved, not the least of which is that in the 20th century, the benefits of technological progress for living standards tended to exceed the damage by bad government in all but the most extreme cases, making it hard to speculate on what might have happened without the latter. (Also, due to a confluence of lucky technological and social factors, the period in question happened to place low- and medium-skilled labor in industrialized countries in an exceptionally favorable situation.) (Note that if it hadn't been for the empirical example of the Western world across the Iron Curtai

It's hard to weigh these kinds of alternative histories. Given their strategy of supporting protest movements, and indeed, getting in front of every parade they could, I'm sure they lended impetus to a number of good movements. On the other hand, when they got out in front of the movements, they would alter the course of the movements. Whether the net perturbation was good depends on your values, and the empirical facts of how large and in what direction those perturbations were. Me, I'm not very fond of communism, so I find the lingering effects of their ideology harmful.