People elsewhere took heed, and today, according to the NRA, 40 states have "right-to-carry" laws. As those laws have spread, the homicide rate has fallen sharply from the peak reached in 1991.

--The Second Amendment got a second look. In 1983, a San Francisco lawyer named Don Kates published an article in the University of Michigan Law Review arguing that, contrary to prevailing wisdom in the judiciary and law schools, the Constitution upholds an individual right to keep and bear arms.

Numerous legal scholars, spurred to examine the record, reached the same surprising conclusion. Before long, even some liberal law professors were coming around.

In 2000, Harvard's Laurence Tribe published a new edition of his influential constitutional law textbook, asserting that the Second Amendment had an undeniable meaning: "The federal government may not disarm individual citizens without some unusually strong justification consistent with the authority of the states to organize their own militias. That assurance in turn is provided through recognizing a right (admittedly of uncertain scope) on the part of individuals to possess and use firearms in the defense of themselves and their homes…"

The majority opinion last week, written by Justice Antonin Scalia, drew heavily on this stack of scholarship to argue that the framers did not limit the right to the context of service in a state militia. Without the stimulus provided by these contrarian thinkers, the decision would never have come to pass. And the Second Amendment would have remained what it was for so long: a curious irrelevancy.

Instead, the right to keep and bear arms has finally taken its rightful place with our other fundamental liberties. It may be the natural course of things for government control to expand and freedom to shrink. But as Jefferson knew, America was founded to reverse that process.