They hate the nuclear family. It's patriarchal and everyone knows that a father-led family just results in victimization.
They hate it because the traditional family is the single-most resistant institution in society to their schemes. This is the root for their hatred of religion and homeschooling, for example.
You'll be happy to know that if I decide to vote, I'll just vote straight GOP. But understand that we're just rearranging chairs on the deck of the Titanic. You gave away most of our institutions by willful ignorance and listening to dopes with a vested interest in convincing you that this was just a fringe cultural movement restricted to the nether regions of our university campuses. Do you really think electing more Republicans is going to turn this back when you see their cowardly acquiesence to this insanity right now?