BACKGROUND
In the exercise of their constitutional duty to "chuse their... Officers," the United States Senate and House of Representatives each elect and compensate, as one of their several officers, a chaplain. See U.S. Const. art. I, § 3, cl. 5 (Senate Officer Selection Clause); 2 U.S.C. § 61d (authorizing Senate Chaplain compensation); U.S. Const. art. I, § 2, cl. 5 (House Officer Selection Clause); 2 U.S.C. § 60a-2a (authorizing House Chaplain compensation). As officers of their respective Houses, chaplains are elected by a majority of the Members thereof- none of whom are named as defendants in this lawsuit. See, e.g.. House of Representatives Rule n.l, reprinted in Constitution, Jefferson's Manual and Rules of the House of Representatives, H. R. Doc. No. 106-320, at 345 (2001). The election and compensation of chaplains as officers of their respective Houses is deeply rooted in our nation's history. Because an understanding of that history contributes to an understanding of the issues in this case, we briefly describe that historical background before turning to plaintiffs arguments and the decisions and principles of law that control them.
A.   HISTORY OF CONGRESSIONAL CHAPLAINCIES
The election and compensation of chaplains as officers of the House and Senate represent the continuation of a longstanding national tradition that predates the adoption of the Constitution. The legislative chaplaincy has its origins in colonial times and was a constituent part of the Continental Congress, the state conventions ratifying the Constitution, the First Congress, and the state legislative bodies that ratified the First Amendment.
The first Continental Congress met on September 5,1774, and, the very next day, resolved that Reverend Jacob Duche, an Episcopalian clergyman, should open the following day's meeting with prayer. 1 J. of the Continental Congress ("Journals ") 26 (1774). Reverend Duche did so, -3-