"In a politically polarized and heavily armed society, each new massacre rapidly becomes another occasion for mutual accusation. Adam Serwer: White nationalism’s deep American roots The crucial variable in mass shootings is not ideas but weapons. We cannot control ideas or speech and should not attempt to do so even if we could. But we could reduce access to the weaponry that converts ideology into atrocity. At least, other advanced countries find themselves able to do so. Almost every country on Earth has citizens filled with vitriol, but no comparably advanced country has a gun-violence epidemic quite like America’s."