I'm simply saying that is the standard. Hate speech can be banned in situations where it will incite "imminent" violence. Moreover, the courts have been pretty good at maintaining this standard so far. The "slippery slope" argument hasn't proven to be applicable here.
Strictly speaking, the government cannot just ban hate speech that incites violence. It must prohibit either all speech producing violence, or none. In other words, the First Amendment forbids the government from discriminating between hate speech and other speech.
That's not exactly correct. The courts have held that hate speech that is not likely to incite imminent violence to be protected by the First Amendment, whereas the very same words, in a situation where imminent violence is likely to be the result of such speech, are not protected. The likelihood of "imminent violence" is the differentiating factor, not the words themselves. Consider that a transcript of a speech in a magazine is not likely to incite an immediately violent response and, therefore, would be allowed; while the same speech given at a rally, perhaps, may and, therefore, might not be.
Of course with many judicial litmus test, it is often left to what a "reasonable" person might believe to be the likelihood of imminent violence. I'm not sure in this case. Anyone?