Republicans aren't exactly racing to defend President Bush's assertion of executive privilege against Congress's investigation of his firing of nine U.S. attorneys. This leaves former political director Sara Taylor and Harriet Miers, former White House counsel, facing possible contempt sanctions. If this sword of Damocles drops, an important constitutional showdown between the branches might well reach the Supreme Court.

Rather than run from this fight, supporters of the constitutional system ought to stand firm with the president....