A leaked Justice Department white paper has renewed the debate over presidential power and the war on terrorism. The timing of the leak, just days into President Barack Obama’s second term, was convenient for the many people who have switched sides in that debate.

The idea that it would be great to put high-speed-rail lines all over the country shows an underappreciation of American geography and of some of the nation’s genuine strengths.

At one point in the Iran-Contra hearings, Arthur L. Liman, Senate chief counsel, said (rather testily I thought): "This is not a prosecution, Col. North, this is an investigation." To which Col. North might well have said in response, "You could have fooled me, counsel." 

Mr. Liman might...