Our country actually displays several key parts of Socialism. Graduated income tax, inheritance taxes, public education etc. are all elements of Marxism, and therefore Socialism.
I would argue, at least on an academic level, that the US is a pseudo Social Democracy.
The real irony behind all this is that most of the right wing Christians hate Socialism, yet they don't realize their own deity is in fact one of the biggest communists to have ever lived.
There is no substitution for human competition.