ANALYSIS: Breakthrough on gun control efforts real but may be fleeting

— -- It looks like a stunning breakthrough in a long-paralyzed debate.

A bipartisan bill has been introduced. The White House appears to be on board. Even the National Rifle Association agrees that something must be done to limit access to the kind of devices used by the Las Vegas gunman to slaughter more people than any one shooter has ever done on U.S. soil.

Yet the quick consensus around limiting “bump stock” devices - all within a week of the incident that introduced them to the public consciousness – may be both more and less than meets the eye.

This is a big deal in the sense that new gun restrictions simply do not get promulgated or legislated in today’s Washington. It has been a generation since the assault-weapons ban and the Brady Bill became the last significant gun-control measures to pass Congress, back in 1994.

Somehow, Las Vegas seems to have done what Columbine, Virginia Tech, Orlando, San Bernardino, and – most famously – Sandy Hook did not. National consensus quickly formed in the direction of limiting access to a gun-related device that allows a shooter to fire more shots more quickly.

But there’s ample reason to think there’s no reason for gun-control forces to celebrate a rare victory. For starters, this is only about one previously obscure device – so little-known, in fact, that advocates and lawmakers on both sides of the gun debate generally have professed ignorance about it before this week.

Then there’s the matter of what will likely happen as a consequence of consensus. It’s not yet clear that the White House would support a bill in Congress banning so-called bump stocks. The NRA’s carefully crafted statements point toward possible regulations without an actual endorsement of any.

"We ought to take a look at that and see if it is in compliance with federal law and if it's worthy of additional regulation,” Wayne LaPierre, the NRA’s executive vice president, said on Fox News Thursday night. “That being said, we didn't say ‘ban,’ we didn’t say ‘confiscate.’”

Much has to be done to get to action, and the Trump administration’s position is still unclear. Many lawmakers are saying they want hearings on the issue – a baby step, perhaps, but beyond what most pro-Second Amendment lawmakers have called for in the wake of other mass shootings.

Still, the broader context suggests how big this moment may be for a gun-control movement that’s used to losing far more than winning, at least at the federal level. Just a week ago, the House was teed up to vote on a bill that would make it far easier to purchase silencers.

That was one of two major NRA priorities for this year. The other one, which would have the effect of essentially nationalizing the most lax state concealed-carry regulations, also looked like it had a good chance of passage.

Those bills are now shelved indefinitely. That alone bucks a trend under Republican control of Congress, one that seemed likely to continue with a president who received the strong and enthusiastic backing of the NRA.

The narrow focus on a particular accessory may be a model for gun-control advocates. There may be other devices and perceived loopholes in gun laws that come to light after Las Vegas.

After all, after being shut out of so many conversations in a Republican-controlled Congress, gun control advocates have largely turned to tackling the complex patchwork of local laws and regulations.

And there they have had some success. Since 2013, eight states have passed broader, more universal background check laws and almost half have legislated to keep guns from domestic abusers. Advocates are confident the trend is in their favor.

"As recently as 2009, Democrats left gun safety off their priority list, despite firm control of Congress and the White House,” Peter Ambler, co-founder of Americans for Responsible Solutions, told ABC News. “Today, supporting gun violence prevention is basically a litmus test for Democrats.”

Pro-gun-control lawmakers and groups have a long way to go to demonstrate their issues have resonance with voters. The NRA isn’t neutered, and may still be playing a careful game that doesn’t take the organization away from its long-held stance of opposing virtually any gun restrictions.

But it would be notable if Washington’s tangible response to the latest tragedy is more than thoughts and prayers. The debate over guns now is different than it was just a week ago.