My point is that Darwinism was used to promote some good here in the United States. And it was also used for evil purposes in Europe. Darwinism itself as a construct in social policy, in how individuals react to each other, is neutral in regards to good and evil. Americans used it to great a great thriving economy, while Europeans used it to create murder. I guess the difference is in the mindset of Americans compared to Europeans.
Darwinism is used here to promote abortion (eliminating the weeds of society) and Marxism so your theory falls short on all accounts. I would be interested in one thing it has been used to promote which is not enlarging government or eliminating God from America.