For me, that situation is lamentable. "Social" and "Darwinism" are ordinary words with conventional scientific meanings - their combination should not be a term of abuse.
So: I am a social Darwinist. I think Darwinism is true and am sympathetic to and supportive of attempts to make society better by applying it to human society.
One of the most obvious approaches to improving society by using Darwinian evolutionary theory involves memetic engineering. This approach has long been advocated by social theorists. B. F. Skinner's 1971 book "Beyond Freedom and Dignity" was an early contribution to the topic which illustrates the approach.
Scientists should absolutely not let the term "Social Darwinism" to be dragged into the gutter by Darwin-haters. "Social Darwinism" is not synonymous with Nazism, and doesn't entail forced sterilization or gas chambers. That is just a nasty smear campaign.
All kinds of folk did nasty things during the 20th century. However, their crimes do not - or should not - blacken the doors of their descendants - or intellectual descendants - forever. Yes, some folk believed in Darwinism and killed or sterilized some other folk. However many 20th century tribes did similar things - Christians, Muslims and atheists, for instance, are bigger groups that did far worse things. That's not to say that doing bad things is OK - if other people did worse things. It just means you have to get things in perspective.
As far as I know, there's no evidence that Darwin enthusiasts are morally any worse than other folk. The reverse seems much more likely - since an understanding of Darwinian evolution is correlated with educational attainment, which in turn is associated with reduced rates of violence and crime.
In an enlightened civilization, I think that the idea that "Social Darwinism" is a term of abuse would be absurd. It's all just part of the confused delusion that evolution and Darwinism are wrong and bad.
I'm fed up with hearing the "isn't that Social Darwinism?" Yes, that is Social Darwinism - but social policy informed by correct science is much likely to be better than social policy which is not informed by correct science.