Though what do you mean by 'we' and 'not tolerate'? 'We, the denizens, or owners, of this forum', or 'we, the state'?
What is absurd is the idea that people can express hateful thoughts and then insist nobody can challenge or condemn those words. But I'm still not sure about the degree to which it should be a matter for the law.
We as a society of individuals need to apply a variety of techniques to fight against the inhumane treatment some of our fellow human beings endure.
The easiest and best way to effect positive social change is by changing our own attitudes. When we treat others with respect it sets a good example. I'll point to the Love Has No Labels TV commercial with John Cena explaining that to love America is to love ALL Americans.
Most folks who carry anger in their heart are actually hurting inside. It's really hard to express love towards others if you don't love yourself first. We need those folks to know it's okay to let that anger go.
But some folks will never take the hint that playing well with others is better for everyone in the long run. Those folks may need to be somewhat shamed or shunned if nothing else works. And if they continue to hate in their hearts hopefully they've at least learned to not act on that hate or teach it to the next generation. I'm fine with the idea of angry old racist, homophobic, misogynistic farts quietly dying off.
And if the hate rises to the level of illegal discrimination then we address the issue via the courts and legal system. Society can't police your thoughts or the content of your heart, but we can make sure nobody is denied a job or housing or any of the same rights and opportunities all Americans are entitled to.
And in very extreme cases of nuts who decide to pick up a gun, go to a school or a church and kill others to express their anger, well, IMHO, we shoot to kill and put that person down like we would a vicious dog.