Hate speech - a rhetorical pickaxe I like to think of it as anti-baby speech.
It's when you attack something a person was born as/under/or subject to without any effort or doing of their own. Something they have no control over. It's something weak people do. I.E. a "dick move." I suppose that's not entirely accurate since a person can become handicapped later in life or of course become elderly, and "hate" speech against handicapped people or the elderly (though patently silly) could in theory result in violence or discrimination against them resulting in their revolt and contribution to the start of a war (though, I suppose in those two particular cases the latter is fairly unlikely, but that's not the point).
I like the earlier post of the amygdala "fear response". It makes people feel unsafe knowing there's nothing they can do or change about their behavior or demeanor. Going back to the baby thing, it's like someone was just born "wrong" and should have been killed as a baby. Which is generally not what sane people believe.
Not a fan of the whole grouping of people who choose to become the opposite gender because of non-medical self-diagnosis being on par with say, black people who have been historically persecuted for being born with the color of their skin and for no other reason. Just seems kind of offensive to compare apples and oranges when it comes to human life, dignity, and well-being. But whatever.
I suppose religion is interesting because people can choose to believe or not believe anything they want. Otherwise they're legally and medically retarded or at least not a legal, functioning adult (I.E. is a child). So, in my opinion, it's not the same as persecuting someone who chooses to follow Mayor McCheese as Lord and Savior versus someone born with a different skin color than you through no action, desire, or will of their own. See the difference. One is a choice, one is not. I just can't find the two comparable legally, and yet they are so. Again, it's probably to prevent wars and group or gang violence, I guess. Something like that. The people in charge know what they're doing so just live your life. You don't really have many other options.
In my opinion some of the worst hate speech is used everyday without the average person batting an eye. "Size-ism". Calling somebody "little" (often prefixed with a strong secondary insult) just because they were born smaller than they were. That's discrimination. Miserable cowardly people (who know deep down the world would be a better place without them) cannot refuse an opportunity to attack, belittle, or demean a person smaller than them when it's easy. They cannot cope with modern society where everyone is equal, their size they based their entire identity on that used to mean everything as a child, getting them their every want and desire, now meaning nothing and getting them nothing, without spreading misery wherever they step. Cowardice laws should fix that right up. These arrogant, brainless giants need go the way of dinosaurs and experience the Great Flood in Genesis (but a non-literal legal, social version) if humanity is ever going to live in peace and prosper.