After all, if we are going to grant that the fiends in the Westboro Baptist congregation have the right to make their noisome protests at a time and in a place where no sane society would allow them to do so, then we should be willing to allow for some simple mechanism to counterbalance the damage they do.
I imagine that if some champion of one of the families molested by that pestilent rabble—let’s imagine him as a Special Forces officer famed for his uncanny marksmanship—were allowed to challenge the Rev. Fred Phelps to acquit himself manfully on the field of honor, and to issue the challenge with the full indulgence of the courts and the weight of social judgment on his side, the good reverend and his parishioners would in all likelihood quietly ooze back into the sewer from which they originally pullulated. If not—well, for the gentler souls among us, I suppose we could limit duels ideally to first blood, and allow for fatality only in the event of mishap.
Really, I can see no good argument against the proposition. “A duel is often just a legal murder,” you might object. But, if there is one thing legal history definitely tells us, it is that what we define as murder is largely a matter of legal convention. “Intentional and avoidable violence is a sin,” you might then say. Yes, but so what? The courts are not in the business of telling us how to care for our souls. Leave such concerns to the pulpit or the confessional.