President Obama is clearly fed up. His speeches after mass shootings — speeches that have become a bit of a morbid ritual, given how regularly the shootings occur — have grown angrier, more emotional, and more disgusted at America’s gun violence problem and Congress’s unwillingness to do literally anything to stop it. “This is a political choice that we make,” Obama declared Thursday night, after the 294th mass shooting of 2015, “to allow this to happen every few months in America.”But let’s be clear about precisely what kind of choice this is. Congress’s decision not to pass background checks is not what’s keeping the US from European gun violence levels. The expiration of the assault weapons ban is not behind the gap. What’s behind the gap, plenty of research indicates, is that Americans have more guns. The statistics are mind-blowing: America has 4.4 percent of the world’s population but almost half of its civilian-owned guns.