In a secret meeting on Tuesday morning, Senator Rand Paul (R., Ky.) hosted a bipartisan group of senators and House members in the Capitol’s basement. According to several participants, the lawmakers plotted ways to stop the use of U.S. military force in Syria. Since the diplomatic situation is fluid, there was no final consensus on how best to combat the administration, but potential legislative maneuvers, press appearances, and letters were discussed. Several undecided members asked questions. Aides say Paul planned the gathering over a week ago, and the list of attendees grew by the day. He is pleased, especially, by...