WASHINGTON - Senate Republicans rejecting a U.N. treaty on disability discrimination earlier this month won headlines, but a similar blow last July to the U.N. Arms Trade Treaty drew mostly yawns.

That may have happened because once the powerful National Rifle Association weighed in -- the pact, it said, would put "international controls" on guns and "undermine the constitutional rights of law-abiding American gun owners" -- the outcome became a foregone conclusion.

The NRA had dialed up opposition from its 4 million-plus members, who flooded House and Senate offices with e-mails, letters and phone calls. U.N. negotiators insisted the treaty was aimed at terrorists and drug lords and would not impose any restrictions on civilian gun owners whatsoever. Nonetheless, without U.S. support, they shelved it.

Thus, the NRA notched another in a long line of political victories dating back at least to 1934 when it succeeded in watering down the National Firearms Act, approved by Congress in response to Prohibition-era gangsters and bank robber John Dillinger's killing spree with a looted arsenal of submachine guns, rifles and revolvers.

Since then, the NRA has enjoyed a legislative winning streak virtually unrivaled on Capitol Hill, from opposition to armor-piercing bullets in the 1980s to a more recent drive to emasculate the Bureau of Alcohol, Tobacco, Firearms and Explosives, the federal agency charged with enforcing federal firearms laws.

"They are a very powerful organization," said former Rep. Charlie Stenholm, D-Texas, a staunch gun-rights supporter who tangled with the NRA a few times until his defeat in 2004, when the group endorsed his rival, Rep. Randy Neugebauer, R-Texas. "They promote their views and they do a pretty darn good job of it."

But in the wake of the Connecticut school shooting, in which Adam Lanza took the lives of 20 children and six adults with a Bushmaster .223 AR-15 semi-automatic rifle before ending his own, that all may be changing.

With President Obama, Sen. Dianne Feinstein, D-Calif., and other Democrats on Capitol Hill responding to growing public sentiment in favor of gun control, the NRA hunkered down in "no comment" mode for a week after the shootings before finally attempting to stake out its own turf.

On Friday, instead of retreating, NRA executive vice president Wayne LaPierre embraced the "more guns, less crime" philosophy popular among gun-rights advocates. He put forward a plan to place armed guards in schools.

"The only thing that stops a bad guy with a gun is a good guy with a gun," LaPierre said.

In doubling down on more guns as the solution to gun violence, the NRA was wary of its reputation among pro-gun rivals as too cozy with the Washington establishment.

Earlier last week, one such group, Gun Owners of America, contrasted its belief that designated gun-free zones made schools a tempting target to NRA's silence.

"One of the great untold stories about NRA is that it's in a constant battle with grassroots members," said Ross Baker, a political science professor at Rutgers University who says he is a gun owner and on-again, off-again NRA member.

"There is a feeling that NRA lobbyists in Washington have gone native, that they're more interested in making deals than protecting gun rights."

An example: The NRA opposed gun-buyer background checks contained in the Brady Bill approved by Congress in 1993 and fought an element of it all the way to a 1997 victory in the Supreme Court.

But ultimately the NRA supported background checks once they became computerized and gun purchasers waited minutes rather than days for the FBI system to approve or deny them.

In 2007, the NRA also signed off on improving the background-check's ability to flag prospective purchasers disqualified by mental illness. Gun Owners of America opposed the measure.

The Connecticut shootings capped what appears to have been a losing year for the NRA. In the 2012 elections, the organization saw its investment of more than $18 million against President Obama and Democratic Senate nominees go down in flames.

Still, the secret of the NRA's long record of success lies in its intimate connection with its gun-owner membership, its ability to turn on and turn off political heat in lightning-quick fashion, whether it be the halls of Congress, the state capitals or local town councils.