I expected this comment to show up. While I agree with you in that I personally would not want any group determining which opinions are allowed in the public sphere and which are not, I would prefer that the would-be punch-throwers focus their energy toward changing policy rather than committing vigilantism. Just because I would prefer them to attempt to change policy instead of throwing punches, it does not follow that I personally am advocating for a government body to regulate speech in the public sphere.

On that note, however. . .

A) you’d have to change the constitution not just pass a law and B) you’d be an idiot for trying to do so.

No you would not. Although the Supreme Court of the United States has defended the rights of controversial groups to express their views on multiple occasions, most famously in the Skolke Case, the Supreme Court clearly has the power to determine the limits of Protected Speech and has used Judicial Review to uphold laws limiting speech. For example, Obscenity is not protected speech, Sedition is not protected speech, Fighting Words are not protected speech, speech leading to "imminent lawless action" is not protected speech.

The Supreme Court has ruled on multiple occasions ((Link) (Link) (Link) that speech that is hateful or offensive is protected by the First Amendment, however it would not require a constitutional amendment to change that. It would simply require a different court ruling.

I admit personally, that I too lean toward free speech absolutism but to claim that getting rid of legal protections for hateful or offensive speech would require a constitutional amendment is factually incorrect and ignores the fact that protected speech is already a convoluted issue in American law.