Rather than preventing crimes by identifying a trafficker before he sells guns to potentially lethal criminals, the A.T.F. has to wait until the police recover those guns from multiple crime scenes. Then law enforcement officials can begin the laborious process of tracing each gun from the manufacturer or importer to various middlemen, the retail seller, the original retail purchaser and one or more subsequent buyers.

Meanwhile, dealers who work with traffickers are protected by another N.R.A.-backed measure that ensures that firearms dealers do not have to maintain accurate inventories on an annual basis.

Think about that: A car dealer keeps an inventory to know when cars go missing so the police can track them down as quickly as possible. Why the lack of curiosity among gun dealers? Well, gun dealers must report lost and stolen guns to the A.T.F. because large numbers of missing weapons are a red flag for trafficking. Without an inventory requirement, it’s easier to sell guns off the books.

Do most gun owners want the N.R.A. to protect criminal dealers? I doubt it.

The A.T.F., which has helped convict tens of thousands of gun criminals, has of course been a perennial target of the N.R.A., and the lobbying group has worked relentlessly to limit the A.T.F.’s budget and strangle its operations.

Today’s A.T.F. operates with about the same number of agents as it did 40 years ago, fewer than the number of officers in the Washington, D.C., police force, yet it is charged with investigating violations of federal gun, arson, explosive and other laws nationwide.

Since the N.R.A. seems to loathe the A.T.F., one might think it would work to disband it or have its mission performed by an agency like the Federal Bureau of Investigation, with its more polished and professional public image. But the N.R.A. prefers the hobbled A.T.F. just as it is, and every year it helps ensure that Congress approves legislation banning the transfer of A.T.F. operations to any other agency.

You don’t get much more cynical than that.

Since his daughter, the journalist Alison Parker, was shot dead in August while presenting an on-air broadcast, Andy Parker has been on a campaign to “shame” lawmakers whom he says are “cowards and in the pockets of the N.R.A.” Some of those lawmakers might prove to be less cowardly if they understood that the N.R.A. was no longer the voice of law-abiding gun owners, but rather a voice for criminals.