Walmart, one of the largest retailers of guns in the United States, sells rifles and shotguns in approximately half of its more than 3,500 supercenters . The company says it offers guns where hunting or clay shooting is popular, but not in certain states like California and not in “urban markets.”

It stopped selling military-style rifles in 2015, citing lower consumer demand. The gunman at the El Paso store, who the authorities say killed 22 people, was carrying an AK-style semiautomatic rifle.

“Walmart should use its power to stop selling guns in its stores until politicians and gun manufacturers get their act together and raise the standard for gun ownership in this country,” Senator Cory Booker of New Jersey said Friday.

Walmart said this week that it was removing displays promoting violent video games from its stores. But Julián Castro, the former housing secretary and mayor of San Antonio, criticized that plan and suggested that the company stop selling guns instead.