Kroger, the nation's largest supermarket chain, has been under fire from the Michael Bloomberg-backed gun control group, Moms Demand Action for Gun Sense in America for months - and Senate Democrats are jumping on the bandwagon. In a letter penned to Kroger's CEO W. Rodney McMullen, Sens. Dianne Feinstein, Richard Blumenthal and Chris Murphy pressured the grocer "to adopt a policy that would prohibit the open carry of firearms in your stores In doing so, Kroger would be sending an important message about your commitment to the safety of your employees and customers."