Lindsay Wise & Jonathan S. Landay Gertrude on the Fighting Words exception to First Amendment.
You don't have to be a 1A attorney to understand the jurisprudence behind this particular exception. Why not try the easily-accessible Wikipedia article? Or if you're interested in writing on the issue in public, perhaps you could drop a line to an attorney who actually practices law in the area. Or perhaps you could read one or two of the recent SCOTUS opinions on it.
At least a little something, yes? A smidge? I'm no lawyer, but I also insist on at least the illusion of due diligence. Can we at least perhaps all agree that if Snyder v Phelps found in favor of the WBC, then inviting an inflammatory Dutch politician to speak should count as protected speech?
There is a great deal that is unsavory and ugly about mean-spirited speech. But much worse is using the lethal might of the state to silence matters of opinion. It is occasionally just to silence others with the threat of death. Consider carefully what those occasions might be, Ms. Wise, Mr. Landay. For when you grant to the state such authority, you may not always get to choose who wields it. You may find that this exchange ends up being less than entirely euvoluntary.