During the nineteen-eighties, this interpretation, which came to be known as the individual-rights argument, gained the attention of several distinguished law-school professors, including, most notably, Sanford Levinson, whose 1989 essay, “The Embarrassing Second Amendment,” was published in the Yale Law Journal. Levinson suggested that legal scholars’ long-standing inattention (“To put it mildly, the Second Amendment is not at the forefront of constitutional discussion,” he remarked), was probably political:

I cannot help but suspect that the best explanation for the absence of the Second Amendment from the legal consciousness of the elite bar, including that component found in the legal academy, is derived from a mixture of sheer opposition to the idea of private ownership of guns and the perhaps subconscious fear that altogether plausible, perhaps even ‘winning,’ interpretations of the Second Amendment would present real hurdles to those of us supporting prohibitory regulation.

Levinson also discussed what is called an insurrectionist interpretation, in which the Second Amendment is thought to allow for a militia of armed citizens standing “ready to defend republican liberty against the depredations” of a government become tyrannical. Levinson didn’t endorse either the individual or insurrectionist views, nor did he dismiss them. Instead, he urged scholars to take them seriously. His essay was essentially a plea for reasoned debate: “Is not, after all, the possibility of serious, engaged discussion about political issues at the heart of what is most attractive in both liberal and republican versions of politics?”

The tragedies at Waco in 1993 and in Oklahoma City in 1995, both of which involved a modern militia movement, brought the insurrectionist interpretation of the Second Amendment to the public’s attention and prompted vigorous critiques. In “To Keep and Bear Arms,” an essay published in The New York Review of Books five months after Timothy McVeigh bombed the Murrah Federal Building, Garry Wills called Levinson’s essay, which had been embraced by the N.R.A., “frivolous,” and reported that he found “a vast outpouring of articles justifying individual gun ownership on the basis of the Second Amendment” to be muddled and tendentious. Wills also noted that, in advancing gun-rights arguments, the same people who offered the individual-rights interpretation usually also endorsed the insurrectionist one. “Only madmen, one would think, can suppose that militias have a constitutional right to levy war against the United States, which is treason by constitutional definition,” Wills wrote. “Yet the body of writers who proclaim themselves at the scholarly center of the Second Amendment’s interpretation say that a well-regulated body authorized by the government is intended to train itself for action against the government.” As to whether those who advocate these positions had been ignored, Wills wrote, “Perhaps it is the quality of their arguments that makes them hard to take seriously.”

In the first decade of the twenty-first century, American historians who disagreed with the individual and insurrectionist interpretations of the Second Amendment began to take them more seriously when it became clear that a conservative judiciary was taking them seriously, and that a test case would reach the Supreme Court. An important statement of what is generally referred to as the collective-rights interpretation—the idea that what the Second Amendment protects is the people’s collective right to keep and bear arms to form militias for the common defense—is an amicus curiae submitted to the U.S. Supreme Court in the 2008 case of District of Columbia v. Heller, signed by fifteen eminent university professors of early American history, including Pauline Maier, Fred Anderson, and Pulitzer Prizes winners Jack Rakove and Alan Taylor. It concludes,

Historians are often asked what the Founders would think about various aspects of contemporary life. Such questions can be tricky to answer. But as historians of the Revolutionary era we are confident at least of this: that the authors of the Second Amendment would be flabbergasted to learn that in endorsing the republican principle of a well-regulated militia, they were also precluding restrictions on such potentially dangerous property as firearms, which governments had always regulated when there was “real danger of public injury from individuals.”

The different weight the Court gave to these different interpretations is suggested by its decision in Heller. Justice Scalia, writing for the majority, determined that, “The Second Amendment protects an individual right to possess a firearm unconnected with service in a militia.”

How Heller will be interpreted is as yet unclear. In “Dead or Alive,” a 2008 essay in the Harvard Law Review, Reva B. Siegel instructively situated the decision within the history of originalism and reflected on the tension between conservatives’ championing of gun rights as a social issue and their condemnation of judicial activism. After Waco and Oklahoma City, the insurrectionist argument faded somewhat. But the individual-rights interpretation, as Siegel observed, prevailed not only in the courts but also in public opinion. A 2008 poll found that nearly three-quarters of American adults believe that the Second Amendment protects the right of an individual to own a gun.

In his remarks before the N.R.A. last week, Gingrich offered a human-rights interpretation of the Second Amendment. “A Gingrich presidency,” he said, “will submit to the United Nations a treaty that extends the right to bear arms as a human right for every person on the planet.”

The United States has the highest rate of civilian gun ownership in the world, twice that of the country with the second highest rate, which is Yemen. The United States also has the highest homicide rate of any affluent democracy, nearly four times higher than France or the United Kingdom, six times higher than Germany. In the United States in 2008, guns were involved in two-thirds of all murders. Of interest to many people concerned about these matters, then, is when the debate over the Second Amendment will yield to a debate about violence.

Photograph by Mark Leffingwell/Getty Images.