“A fraud on the American public.” That’s how former Chief Justice Warren Burger described the idea that the Second Amendment gives an unfettered individual right to a gun. When he spoke these words to PBS in 1990, the rock-ribbed conservative appointed by Richard Nixon was expressing the longtime consensus of historians and judges across the political spectrum.

Twenty-five years later, Burger’s view seems as quaint as a powdered wig. Not only is an individual right to a firearm widely accepted, but increasingly states are also passing laws to legalize carrying weapons on streets, in parks, in bars—even in churches.

Many are startled to learn that the U.S. Supreme Court didn’t rule that the Second Amendment guarantees an individual’s right to own a gun until 2008, when District of Columbia v. Heller struck down the capital’s law effectively banning handguns in the home. In fact, every other time the court had ruled previously, it had ruled otherwise. Why such a head-snapping turnaround? Don’t look for answers in dusty law books or the arcane reaches of theory.

So how does legal change happen in America? We’ve seen some remarkably successful […]