WHEN a young man walked into an elementary school in Newtown, Connecticut in December 2012 and murdered 20 small children and six staff with a Bushmaster rifle from his mother’s gun collection, some wondered if a tipping-point had been reached. Surely America would now enact laws to keep lethal weapons out of the wrong hands? No chance. Bids to curb sales of the most powerful guns and largest-capacity magazines failed. […]