I was wondering who buys eliquid at walmart (lol), but that's not their target market.
Walmart predominately sells big tobacco's ecig products... Juul, probably their most popular product, was purchased by Marlboro's parent company. Juuls are raking in millions and millions of dollars. Walmart's 2nd most popular product (probably), VUSE, is owned by RJ Reynolds.
Big tobacco has been a strange ally of vaping - when they first bought their way into the market there was a ton of fear that they would mess the mechanical market up in their favor. All kinds of stuff... patenting tech, to lobbying for other vape products to be banned and then making terrible vapes that forced people into switching back to cigs. Since then, Big Tobacco has constantly had to go bat for that same community in order to, obviously, protect their own investments. Nobody trusts them, but they've pounded the table the hardest when things look bleak for people who just want to be able to buy a bottle of eliquid...
They'll fight this because it's their products on the line. You can't buy a SMOK mod or a 30ml bottle of eliquid blended by a reputable small american company from walmart. I don't think you can even buy an 18650 battery there...
I suppose what Big Tobacco can do probably is survive an ecig legal apocalypse that shuts everything down (web based sales, smoke shop/vape shop sales) until a study slanted in their way gets them an asterisk law allowing only Juuls, VUSEs and other products that can afford the privilege of FDA "approval" to be sold after the fact. The niche market dies under political turmoil while big tobacco gets free reign on ecig sales... :#
I'd love to see big tobacco fall to the giant number of american small business' selling unique eliquids and proven atomizers but they've paid their way to the top of it all and hold all of the cards it seems when it comes to influencing gov't policies and laws.