Which member of the President's task force is instrumental in persuading the President to negotiate with the rebels and to offer amnesty in the novel, Unintended Consequences?

A former Justice of the Supreme Court, Justice Potter sits on the President's task force and is a voice of reason, as he advises the President on the best course of action. He clearly has sympathy for those who oppose the over-reaching power of federal agencies and wants them curtailed. He is instrumental in persuading the President to negotiate with the rebels and to offer amnesty.