Undeniably, if inconveniently for gun-control advocates, this dispensation has a basis in the lapidary phrases of the Second Amendment. It is nevertheless manifestly unstable, characterized both by widespread private gun ownership, overwhelmingly for legitimate use, and by regular mass shootings by madmen and terrorists of various stripes, not to mention more routine shootings.

Though not the bloodiest episode, the Dallas massacre epitomizes our predicament. Police came under fire from an African American who believed himself to be resisting governmental abuse and tyranny — which, according to many a gun-rights advocate, is one of the reasons to have an armed populace.

Attempting to locate the sniper, Dallas law enforcement had to contend with some 20 people who were marching in a larger protest against police brutality while openly carrying rifles and wearing body armor, as was their right under Texas law.

It’s a small miracle, or a huge tribute to the police’s restraint and professionalism, that none of these people was shot by an officer who amid the chaos might have understandably switched from protecting the marchers to defending himself from them.