Washington (CNN) It's easy to be cynical about the politics of guns in the age of mass shootings. From Columbine to Virginia Tech to Newtown to Parkland to El Paso and Dayton, the immediate outcry for more and better gun laws in the wake of mass shootings gives way to hard political realities -- particularly in the Senate -- that seem to be unchanged by these horrific crimes.

The gun debate in this country is, in a word, stagnant.

But what if something outside politics changed the way in which Congress -- especially Republicans in Congress, who have generally voted in lockstep with the National Rifle Association to oppose any further strictures on guns -- thinks about what can be done in terms of common-sense gun laws?

Something like, say, a decision by Walmart -- not exactly a liberal, urban hipster chain of stores -- that it will cease selling handguns and "short-barrel rifle" ammunition in its stores , and will urge its customers not to carry any guns while shopping at its stores. (The move came in reaction, at least in part, to 20 people being murdered at a Walmart in El Paso last month.)

And that wasn't even the most important part of the announcement. This was, from Walmart CEO Doug McMillon

"We encourage our nation's leaders to move forward and strengthen background checks and to remove weapons from those who have been determined to pose an imminent danger. Congress and the administration should act. Given our decades of experience selling firearms, we are also offering to serve as a resource in the national debate on responsible gun sales."

That's quite a statement. McMillon is saying, in essence, that private industry is doing its part to address the epidemic of gun violence in the country and now it's time for elected leaders to step up and do the same. (Walmart follows Dick's Sporting Goods in announcing its decision to curtail gun and ammunition sales in some of its stores .)

And Walmart isn't just any chain of stores in America. It is a massive conglomerate with roots in many of the rural and suburban areas where President Donald Trump did well in 2016 and which are represented by Republicans in Congress. When Walmart speaks, these members of Congress, generally speaking, listen. And what Walmart has done with its move this week on guns and ammo is provide at least some cover from the NRA for congressional Republicans who want to do something about the state of gun laws in the country.

Asked about the move Wednesday, Trump said, "That's up to Walmart. Hey, they're very smart, they had a tremendous quarter, just announced tremendous numbers."

When asked about the ammunition and guns move, Trump said, "You'd have to talk to them," adding, "They can do what they have to do."

Is it possible that Walmart's move doesn't change minds within the Republican conference in Congress about what they can be for in terms of gun control measures? Sure! But we've not seen a move like this by a company as large or as well-regarded by the audiences -- politicians and otherwise -- who have been adamantly opposed to any sort of gun control legislation in the past.