On Wednesday, Congress considered its first gun provision since the Charleston church shooting. In a party-line vote, the House Committee on Appropriations barred the Centers for Disease Control from funding research on gun violence, retaining a measure that was first attached to a spending bill by a pro-NRA Congressman nearly 20 years ago.

“Preventing research because you worry about the outcome is cowardly,” New York State Rep. Nita Lowey, a Democrat and ranking member of the appropriations committee, said as she introduced an amendment to remove the provision that was defeated 32-19. The rider, which Lowey has unsuccessfully targeted for removal throughout its existence, was initially inserted into an appropriations bill in 1996.

That year, the NRA enlisted Arkansas Rep. Jay Dickey, a life member of the gun-rights group, to submit an amendment to an appropriations bill that stripped $2.6 million from the CDC’s budget — the exact amount the agency had devoted to firearms research in 1995. The language he inserted read: “None of the funds made available in this title may be used, in whole or in part, to advocate or promote gun control.”

At the time, Lowey tried to strike the language, which she called “laughable” because it implied that “the Second Amendment is threatened by science,” she recalled on Wednesday. But these 23 words have appeared in every appropriations bill since, creating a gap in research that private dollars can’t completely bridge, experts say.

There are fewer than five private foundations that actively provide funding for gun violence research, Dr. Garen Wintemute, director of the Violence Prevention Research Program at U.C. Davis, told Slate shortly after the Newtown massacre. Wintemute estimates there are only a dozen “experienced investigators” actively focused on gun violence, only two of whom are physicians. In 2013, despite an intimidation effort by a powerful handgun manufacturer, he spent a million of his own dollars to keep his research going.

“If you as a researcher were just looking into the cause of death of 33,000 Americans a year, that’s not advocating for anything,” Tim Daly of Center for American Progress tells The Trace. “That’s understanding the scope of the problem.”

Sticking riders into appropriations bills destined for passage is a way to bypass traditional lawmaking. The NRA has perfected this approach, with its top lobbyist once calling it “the legislative version of catching a ride on the only train out of town.” Several prohibitions that still hinder the ATF were introduced as riders that have since become permanent. The so-called Tiahrt Amendments, authored by former Kansas Rep. Todd Tiahrt, prevent the ATF from releasing crime-gun trace data to anyone other than a law enforcement agency or prosecutor — leaving academics and researchers without easy access to valuable data. The riders also forbid the ATF from computerizing gun sales and trace information, forcing agents to sift through hundreds of thousands of pieces of paper when they want to trace a gun.

“It’s striking to me that neither side — which have both been in the majority since the provision was put in there — has seen fit to repeal it,” Rep. Tom Cole, a subcommittee chairman from Oklahoma, said during Wednesday’s special “markup” session, where 34 amendments to the appropriations bill were accepted or discarded. When it was his turn to speak, Illinois Rep. Mike Quigley countered, “Here’s what’s also very striking. I’ve been here almost seven years. How many hearings do you think we’ve had on gun violence on the House side? None.”

In later years, former Arkansas Rep. Jay Dickey, the same man who proposed the original legislation banning government-subsidized gun research, had a change of heart. A week after the Aurora massacre, he wrote in the Washington Post that CDC-funded research was key to understanding — and preventing —gun violence. “We must learn what we can do to save lives,” he wrote.

[Photo: Flickr user Phil Roeder]