[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.