The problem with your summary of the centrist objection is that it's false. The Overton window isn't narrowing -- it's expanding. Look at the last presidential elections. You had Bernie Sanders expressing socialist ideas and opposition to the 1%. Expressing those ideas used to be political suicide, but not anymore. At the same time Trump expanded the Overton window enormously to the right. Look at the political discourse in its totality and compare that to the discourse from just 5 years ago. Voices in the far right and far left are louder than they have been for at least a generation. How is this compatible with claims about a narrowing Overton window? It's patently absurd.
As for your remark about calmly states ideas: hate speech laws exist for a reason in most of the world. The United States is the exception in its free speech absolutism. A lot more harm can be done by calm speech than by a baseball bat, and free speech (like any other freedom) can be used to infringe on other people's rights. I value free speech but I don't value it over everything else, and I don't think State suppression of free speech is meaningfully different from the many other ways in which speech can be suppressed.
As for your remark about calmly states ideas: hate speech laws exist for a reason in most of the world. The United States is the exception in its free speech absolutism. A lot more harm can be done by calm speech than by a baseball bat, and free speech (like any other freedom) can be used to infringe on other people's rights. I value free speech but I don't value it over everything else, and I don't think State suppression of free speech is meaningfully different from the many other ways in which speech can be suppressed.