I'm certain there are bad and really bad parts nearby but for the nearly two weeks I was in that area walking about and using public transport, I was favorably impressed. I'm also certain that some people from those bad and really bad areas shop at that WallMart. All I'm saying is that the two non-holiday times I was in that WallMart, it was absolutely packed to the point of being borderline chaotic. Had lines been a little longer, then I can easily envisage the scenario described of a chaotic mass of people rather than being orderly lined up in the checkout area.
My distinct impression is that in that area, discount retail demand outstrips supply.