I read through thirty responses on this thread. And maybe there is not one answer alone.
Several people have suggested in their own parlance, that they hate the "other", and several have included non-Christians as a constituent of the other. Sometimes this is true, but sometimes the Christian is a constituent of that other. Ayn Rand was never a Christian, and became a selfish atheist. Ayn Rand is considered a "Conservative" heroine. O, and by the way the worst writer in the English language. She is wretched in fifty pages, yet she puts a thousand in a book, and it still sells now.
Many of these hate filled conservatives profess to be Christians. Some are liars on that subject too, others are pharasaic, hypocritical Christians. But yes, that hypocrisy is a more salient characteristic; for it is not only in the religious sphere of morality, in which one shows hypocrisy. We have those who call for thrift, and spend lavishly on themselves. We have those who call for war, and made sure they never went. The listing of self contradiction in word compared to deed is quite long.
There is a meanness, it is very evident and palpable. I see where fear would explain some of it, i also see egotism, selfishness, mental aberration. I would suggest that the mean spirit is of an hateful nature; and to speak in theological terms, hate is like evil (or hate is an evil), and evil can be defined by the absence of love.