Dennis Prager, in an article about Liz Cheney and her lesbian sister Mary, puts it this way: {my emphases]
There are individual haters on the right and individual haters on the left. But there is no large-scale hatred in the United States of America today that compares with the hatred of the Left for the Right. Whereas the Right regards the Left as wrong — even destructively wrong — the Left regards all those on the right as evil: “Sexist,” “intolerant,” “xenophobic,” “homophobic,” “Islamophobic,” “racist,” “bigoted” are typical descriptions of the Right made by the most respected names on the left. This hatred is what enabled MSNBC’s Martin Bashir to broadcast — reading from a teleprompter, meaning that it was not spontaneous — that Sarah Palin deserves to have someone defecate and urinate into her mouth. (He later offered an apology; he has not been fired.)
But among all of the Left’s hatreds, none compares with its hatred of anyone who believes that marriage should remain defined as the union of a man and a woman. The Left believes anyone, or any business, that supports the only gender-based definition of marriage that has ever existed should be politically, personally, and economically destroyed. Recall, for example, the Left’s attempt to drive out of business a restaurant in Los Angeles because one of its employees donated $100 to California’s Proposition 8, the Left’s boycott of Chick-fil-A, and the Left’s vicious attacks on the Mormon Church. [more . . .]
Me: The Left's hatred is born of a deep blindness difficult for those on the right to conceive, but a totalitarian, passion-driven revolt against right order and beauty. See Prager's article above for elaboration. See also Quin Hilyer's commentary on Prager's points and the leftist hatred.