In United States v. Brewster, 408 U.S. 501 (1972), the Court acknowledged the historical roots of the Clause going back to the long struggle between the English House of Commons and the Tudor and Stuart monarchs when both criminal and civil processes were employed by Crown authority to intimidate legislators. Yet the Court cautioned that the Clause. "must be interpreted in light of the American experience, and in the context of the American constitutional scheme of government rather than the English parliamentary system. . . . Their Parliament is the supreme authority, not a coordinate branch. Our speech or debate privilege was designed to preserve legislative independence, not supremacy." 408 U.S., at 508. In Brewster, supra, at 507, the Court observed: "The immunities of the Speech or Debate Clause were not written into the Constitution simply for the personal or private benefit of Members of Congress, but to protect the integrity of the legislative process by insuring the independence of individual legislators." Claims under the Clause going beyond what is needed to protect legislative independence are to be closely scrutinized. In Brewster the Court took note of this: "The authors of our Constitution were well aware of the history of both the need for the privilege and the abuses that could flow from too sweeping safeguards. In order to preserve other values, they wrote the privilege so that it tolerates and protects behavior on the part of Members not tolerated and protected when done by other citizens, but the shield does not extend beyond what is necessary to preserve the integrity of the legislative process." 408 U.S., at 517.