More often than not, crusaders for causes try to rally support by glooming over the darkness of their situation. So why is this man smiling? Sitting in his pine-paneled office at the mid-Manhattan headquarters of the American Civil Liberties Union, Executive Director Aryeh Neier, 37, is saying happily these days, "This is the best single moment for civil liberties in the past dozen years." The statement may be impolitic, but Neier has a point.
Lately, the A.C.L.U. has been running up a remarkable record. When impeachment of Richard Nixon still seemed improbable, the organization was providing Congress and the public with extensive...