VOTE NOW: In the wake of the mass shootings, should Walmart stop selling guns?

<p>FILE - In this May 9, 2013 file photo, a worker pushes shopping carts in front of a Wal-Mart store in La Habra, Calif. The world's largest retailer, said it's testing its own mobile payment system that will allow shoppers to pay with any major credit or debit card or its own store gift card through its app at the cash register. It will start testing the new payment system Thursday, Dec. 10, 2015 at its stores in the Bentonville, Ark. area, where the retailer is based. (AP Photo/Jae C. Hong, File)</p>