The result of criminalizing hate under certain circumstances is that only certain types of people get protected. In a state with hate crime legislation, penalties levied for an assault on me would be milder by statutory requirement than for the very same assault on a homosexual. Why? Because as a straight, white male I do not belong to a class protected by this law.
Hate crime legislation, then, turns out to be not really about hate, but politics. It's not hatred for the victim that is punished. That's covered under existing statutes. Rather, it's hatred for a protected class--African-Americans, Jews, homosexuals, etc.--that's punished under hate crime laws.
Such legislation makes two crimes out of one. The assault is a crime against the victim. The hate is a crime against the victim's group. Yet how does one make sense of a crime against a group that is a different crime from the one against the victim? Groups have no rights according to the Constitution.
Hate crime laws create a whole new category of faceless, personless victims--the injured class. They identify crimes against no one in particular, but crimes nonetheless, offenses that are punishable. They don't prohibit all hate, only politically incorrect hate.