Your research is lacking...Restrictions exist and have been upheld...therefore, through

Constitutional means, additional restrictions can be put in place. IMO bipartisan legislation would be the proper way to go, but we'll just leave that to the scholars.

btw, I suggest you click on the first reference in the linked Wiki summary for more details.

Link: https://en.wikipedia.org/wiki/United_States_free_speech_exceptions#:~:text=Categories%20of%20speech%20that%20are,property%20law%2C%20true%20threats%2C%20false