Updated 6:15 p.m. Arguing the president's case Tuesday included Secretary of State John Kerry - who, before joining the administration, was chairman of the committee - Defense Secretary Chuck Hagel and chairman of the Joint Chiefs of Staff Martin Dempsey. The witnesses fielded challenges from lawmakers in both parties - Sen. Mark Udall, D-Colo., worried about the "open-ended" plan, and America's apparent insistence to be "the policemen of the world." Predictably, though, the testiest moment came during questioning from Sen. Rand Paul, R-Ky., whose foreign policy follows in the footsteps of his famously noninterventionist father, Ron Paul. Claiming he hasn't had "one person come up to me and say they're for this war," Paul challenged Kerry to pledge that if Congress votes down the resolution, the president won't "go ahead and do the bombing anyway." ..."If we lose, what?" Paul asked. Make me proud today, Sec. Kerry. Stand up for us and say that you're going to obey the Constitution, and if we vote you down - which is unlikely, by the way - but if we do, that you would go with what the people say through their Congress, and you wouldn't go forward with a war that Congress votes against. To Kerry's response that Paul can "still be proud" because Mr. Obama maintains constitutional authority to act, the senator lamented: "You're making a joke of us - you're making us into theater."