Actually I doubt many people truly believe that "conservatives hate women and non-whites", it's just a rhetorical hammer used by those arguing against conservatives. Whether the argument is fallacious and/or inaccurate really doesn't matter.

I was about to say something like "welcome to modern politics", except we have evidence of this kind of thing going on since elections in ancient Rome, and it's probably far older than that, too. So "welcome to human nature", maybe.