"We are really rewriting knife law in America," says Doug Ritter, the chairman of Knife Rights.

Ritter, an Arizona journalist and outdoorsman, founded Knife Rights in 2006 after he was riled by an article in The Wall Street Journal that he felt unfairly stigmatized knives as a societal threat. "I basically had an epiphany," Ritter said. "There was not an NRA for knife owners."

Knives, especially switchblades, are in fact heavily regulated in many states and on the federal level with the Federal Switchblade Act, which bans the introduction of those "automatic" blades into interstate commerce. The federal act was passed in 1958, at the height of public fears over street toughs and juvenile delinquency, as epitomized by movies such as The Wild One and Rebel Without a Cause and musicals such as West Side Story.

The movement, Ritter says, came of age in 2009 when it beat back an attempt by the U.S. Customs Service to expand the definition of what constitutes a switchblade for importation purposes to include so-called tactical knives, small blades that can be opened with one hand, but that lack the triggering mechanism of switchblades. "Eighty percent of the knives sold in the U.S. could have been illegal," Ritter says.

The following year brought the push to pass "preemption" laws at the state level, laws that would supersede local ordinances regulating knives, as well as laws that would legalize the sale of switchblades within state lines. The effort brought successes in states such as Alaska, Kansas, and Indiana. Ritter's group also helped defeat a bid by Nevada to ban knives longer than 2 inches.

"Counting Tennessee, we've passed 13 bills in 11 states in four years," Ritter says. "That's a pretty admirable record."

The group has also filed a civil-rights suit against New York City over its efforts to regulate folding pocketknives as "gravity knives." On the federal level, it helped spur a bill sponsored last year by Representative Matt Salmon, an Arizona Republican and Ritter's congressman, that would allow owners of "automatic knives" to transport them from one state to another ithout violating federal law.

As with the NRA's lobbying efforts, much of the justification for deregulation is rooted in the Founders' and modern concepts of self-defense. Last fall, David Kopel, a well-known gun-rights advocate and Second Amendment scholar, released what was termed the first modern analysis of whether the Constitution protects knives along with guns. (It also may have been the first law-review article to quote the movie Crocodile Dundee.)

The conservative argument? The amendment refers simply to "arms," not just firearms, and knives are "arms." And also, just what do you think was on the end of those Revolutionary War-era muskets?

Ritter freely concedes that, for now, his organization, which employs just one state-level lobbyist, has confined its legislative efforts to GOP-dominated states where they're likely to receive a warm reception, but the idea, he says, is to build momentum for forays into more hostile territory. It helps that there's no organized opposition, no Brady Campaign for knives, no "knife control" movement. Liberal pundit Al Sharpton drew some conservative ire last year when he suggested regulating knives along with guns—but for the most part, progressives have been silent on the issue.

Once there's enough grassroots momentum at the state level, Ritter says, the goal will be to repeal the federal switchblade act. "It's a lot easier than to go to Congress and say, 'Why does this anachronism exist?' " he says. "The gangs from West Side Story are all dead!"

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James Oliphant is a White House correspondent at National Journal. Connect Twitter