I remember an "ask a conservative" thread on reddit a while ago. What I found remarkable was that a lot of discussions that were ostensibly about "small government" or "promotion of conservative values", when challanged by a few counter-questions, shifted pretty quickly to population control along the lines of "if the poor get too much welfare they'll just have more kids".

Admittedly, this was reddit, so apologies if I'm misrepresenting real-life conservatives here, but that thread got me thinking that a lot of the political discussion might, at the root, actually be about social darwinism.