It's an abstract statement I guess.
I equate "creationists" to be of a strongly religeous bent. From this I infer (with at least some degree of error to be sure) people like those in the Christian Coalition (or the religeous right if you prefer) which is linked for the most part to the Republicans.

Social Darwinism means that the weak of a society which I shall define as the poor, the impaired, the social unfit, etc. will be weeded out so only the fittest survive.

The Liberals embrace the touchy feely social programs that help keep the weak of society from going under (barely) and which they believe equalize us all in society. The Republicans are against these types of programs (welfare, food stamps, affirmative action, etc.)preferring to believe that we are all responsible for our own destiny and that if we can't pull ourselves up then we deserve the position we're in.

Summing it up:

Creationists=Social Darwinism

This is my opinion of course and you are quite entitled to disagree!
One of the great things about America!