[S]uch people subconsciously think socialism (in particular note the obsession with government medical care) will make more people around them sexually attractive — and, in particular, sexually active. Thus increasing their (currently poor, we surmise) chances of having sex with sexually attractive people.
I dunno. Scandinavia doesn’t seem all that far to the left sometimes. Sweden recently declined to bail out Saab; Denmark has no use for open borders. Still, you don’t see anyone suggesting that we take a lead from the late, unlamented Soviet Union, which practically invented socialism as we know it, and no one, except maybe Paul McCartney, had kind words for their babes.