By contrast, here is how Kagan summarized the Supreme Court's conclusion in the 2008 case D.C. v. Heller (emphasis added): "The Second Amendment confers ... an individual right to keep and bear arms." What the decision actually said is that the Second Amendment acknowledges that right.
"It has always been widely understood," the court explained, "that the Second Amendment, like the First and Fourth Amendments, codified a pre-existing right" that was considered "one of the fundamental rights of Englishmen."
That point was crucial in deciding, as the court did last week, that the Second Amendment applies to the states via the 14th Amendment. Some theory of pre-existing, fundamental rights is also necessary in applying neglected yet important constitutional provisions such as the Ninth Amendment and the 14th Amendment's Privileges or Immunities Clause.
Constitutional interpretation aside, Kagan's reluctance to endorse the concept of pre-existing rights was troubling because without it we cannot draw moral distinctions between legal regimes. How can we condemn a dictator for legally authorized oppression, or say that our own Constitution is better now that it bans slavery than it was when it tacitly approved the practice? The traditional American answer is that people have certain rights by virtue of being human, regardless of what the law says.