A lesbian couple married in Massachusetts relocated to Pennsylvania, where one of the ladies had accepted a job at (prepare to be shocked) Bryn Mawr College. They are suing Pennsylvania to recognize their Massachusetts-issued marriage papers. I happen to have a concealed-carry permit issued in Pennsylvania — in fact, by Montgomery County, where Bryn Mawr is located. I wonder if Cambridge, Mass., would recognize my license to carry?

Perhaps the lawyers among us could articulate a consistent principle under which marriage, historically a state and local issue, is automatically recognized across state lines, whereas the right to bear arms, a matter explicitly protected by the Bill of Rights, is not. I’ve been wondering about this for a while, and have never heard a convincing answer.