Twelve years after the Supreme Court ruled that the right to keep and bear arms is an individual right "unconnected with service in a militia," the Second Amendment is in worse shape than ever. New York; California; Massachusetts; Connecticut; and Washington, D.C., with a combined population of 70 million, have outlawed the sale of most semi-automatic rifles and all gun magazines capable of holding more than ten rounds to the public. Colorado, New Jersey, Vermont, Maryland, and Hawaii also have restrictions on magazine capacity. Seventeen states have so-called "red flag" laws, allowing the summary confiscation of a person's firearms on...