If Mr. Lieberman had once stood up and taken the lead in saying that there were some places a president had no right to take his country even during a time of war, neither he nor this page would be where we are today. But by suggesting that there is no principled space for that kind of opposition, he has forfeited his role as a conscience of his party, and has forfeited our support.

Mr. Lamont, a wealthy businessman from Greenwich, seems smart and moderate, and he showed spine in challenging the senator while other Democrats groused privately. He does not have his opponent's grasp of policy yet. But this primary is not about Mr. Lieberman's legislative record. Instead it has become a referendum on his warped version of bipartisanship, in which the never-ending war on terror becomes an excuse for silence and inaction. We endorse Ned Lamont in the Democratic primary for Senate in Connecticut.