Here’s an article that highlights the ways in which the tenets of socialism have invaded modern society, even where the government is not overtly or structurally socialistic (communist).

We should not be fooled by the fact that most modern political systems these days maintain a republican form. As Gustavo Solimeo points out in this article, “A Specter is Haunting America — Socialism,” 

The very motherland of communism, the Soviet Union, called itself the Union of Soviet Socialist Republics

Socialism can be applied in varying degrees. Thus, in practice, there can be a difference between an incomplete application of socialism and full-blown communism, which is socialism taken to its ultimate consequences. [emphasis added]

I think too many of us in the West have become complacent, believing that socialist ideology has succeeded only in areas with a large, downtrodden peasant population. This is because we make the mistake of thinking of socialism as a political agenda, rather than a thorough-going ideology that embraces every part of culture.

Western nations may not have embraced socialism/marxism on a political level, but many have fallen prey to cultural Marxism, i.e., the attempt to undermine the political structure indirectly, through the culture. As Soleo points out,

Much more important than the political expansion of communism/socialism is the spreading of ideas and customs that are leading the world to abandon the natural order and Christian civilization.

The title of the article echoes the first line of the Communist Manifesto,  substituting America for Europe, as the land being haunted by the specter of Communism. Read the article to see the particular points on which Soleo believes America has been undermined by socialist ideology.

If Soleo is correct in his analysis (I leave it to the reader to decide), American Catholics have, by and large, failed to embrace or apply the principles set out in Rerum Novarum, the founding document of the tradition of Catholic Social Teaching, which was also a direct response to the Communist Manifesto.