You shouldn't confuse something racists (and fascists) latch on to with something being inherently racist.

Social Darwinism is the idea that "survival of the fittest" applies to human behavior. Taken further it ultimately states that the "strong" deserve the resources they can take from "weak" by virtue of being able to take it, but on a casual usage level applied to, for example, anti-vaxers, it means they fell for the rhetoric and therefore deserved to die.

They had a flaw, and nature removed them from the gene pool as a result. Or they had a strength, and were rewarded for it. That's the core idea. Racists, fascists, and capitalists love the idea, of course, because it's very easy to map their nonsense on to that core principle.

Success becomes a virtue in and of itself, and the reality of simple luck, circumstance, social pressures or systemic injustice is ignored. There is only failure or success. It also implies that helping those in difficulty is a "sin," that you are encouraging the "weak" to reproduce and thus weaken the human race.

That would be where the Darwin and Herman Cain awards start mapping onto Social Darwinism. Ultimately, both are communities revelling in other humans removing themselves from the gene pool.

They were weak, they were stupid, they had it coming, and therefore it is okay to mock their tragedies because they did it to themselves.

It's a pretty contemptible thought, once you spell it all out, isn't it?