Of course there is a connection between Darwin, Darwinism and eugenics. Here is an offhand list of great Darwinians who were eugenists:
Leonard Darwin, Eugenic Society, president
Charles Galton Darwin, Eugenics Society, president
Julian Huxley, Eugenics Society, president
Francis Galton, Eugenics Society, founder
R.A. Fisher, Eugenics Education Society, etc.
Karl Pearson, Galton Professor of Eugenics etc.
R. Lewontin, American Eugenics Society, president
J.H. Kellogg, American Eugenics Society
H.H. Newman (of scopes trial fame)
H.F. Osborn, American Eugenics Society
Ernst Rudin, infamous
H. Davenport and Harry Laughlin, infamous
And many, many others.
Of course there is a connection between Darwin, Darwinism and eugenics...
So now we have reduced the charge against Darwin, from him being “responsible” for eugenics to the much lesser “there is a connection”.
I can live with that.