Excellent article on Hofstader's Social Darwinism in American Thought:

Tim Leonard of Princeton has posted a very interesting and important paper on Hofstader's influential book, and what he calls the "myth of Social Darwinism". Leonard points out, among other things, that the association of Herbert Spencer and William Graham Sumner with "Social Darwinism" is almost entirely a product of Hofstader's work, and that Hofstader merely used "Social Darwinism" as an epithet to discredit (libertarian) views he opposed. More generally, Hofstader's book "gave impetus to the novel assocation of Social Darwinism not only with laissez-faire," but with racism and imperialism. "Never mind that the set of Gilded Age and Progresive Era writers who endorsed laissez-faire, racism, imperialism and eugenics is essentially empty.... [Sumner, in fact, was a leading opponent of the Spanish-American War] 'social Darwinism' functions as a synecdoche for all that an early-1940s New Deal liberal (and many cince) would regard as retrograde and reactionary."