Overturn the case (the verdict in favor of the grieving father), and dismiss it. Then everybody else just ignore the protesters. This is America. We tolerate assholes behaving like assholes, and saying things that only assholes would say. And I like it that way. If they can “draw a line” and take away Fred “Asshole” Phelps’ rights to freedom of speech, then they can take away my rights, and yours.
Instead of just ignoring the protesters, I much prefer the idea that I vaguely recall hearing about back in the time when the flag burning case was before the Supreme Court. Some state (Tennessee?) toyed with the idea that if burning the flag could not be forbidden, then a law would be passed making it legal to beat up flag burners. Not sure that the law ever passed, but it suits me just fine. Let the grieving family members have a free pass at the asshole protesters. I’m sure the family members would have many helpers. And suddenly the Phelps gang would not be so eager to protest any more. But I doubt that I can get a majority of fellow citizens to travel down that road. So just ignore them.