One reason our nation will never succeed with socialist programs is because of our cultural diversity. This article (https://www.washingtonpost.com/blogs/govbeat/wp/2013/11/08/which-of-the-11-american-nations-do-you-live-in/?utm_term=.9767430e54e) discusses 11 distinct cultures that make up the U.S. Necessarily, these different ‘nations’ differ in what they value and expect from government. The difference allows our national government to ultimately do what it will while we fight over whose political faction is to blame.
In Europe and other countries there is a much greater degree of shared values, and expectations of government. This is possibly the greatest factor behind the relative success of their social programs.