U.S. v. Nixon upheld the principle of separation of powers and rule of law by stating what about the President? Responses The President could declare war without the approval of Congress. The President could declare war without the approval of Congress. Congress has more power than the President. Congress has more power than the President. The Supreme Court could force the president to issue an executive order. The Supreme Court could force the president to issue an executive order. The power of the President is limited