They're mean because they don't like the slim pickings in men they get. Liberal women are good for a roll in the sack but not much else.
The real difference comes the next morning, when the conservative woman finds she's waking up next to a man who's probably good husband and father material, while the liberal is waking up next to some putz who's going to use her toothbrush, take her phone number, and promise to call her later, but never will.
Hats off to your libido..I doubt I could handle that. I can imagine my attempt, with a little voice in the background, ruining everything, saying, "Sex with a liberal is the moral equivalent of bestiality".