on members of Parliament by using judicial process to make them more responsive to their wishes led the authors of our Constitution to write an explicit legislative privilege into our organic law. In statutes subject to repeal or in judge-made rules of evidence readily changed by Congress or the judges who made them, the protection would be far less than the legislative privilege created by the Federal Constitution. Our cases, however, have made clear that "[a]lthough the Speech or Debate Clause's historic roots are in English history, it 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." United States v. Brewster, 408 U. S., at 508. In deciding whether the principles underlying the federal constitutional speech or debate privilege compel a similar evidentiary privilege on behalf of state legislators, the analysis must look primarily to the American experience, including our structure of federalism which had no counterpart in England. Two interrelated rationales underlie the Speech or Debate Clause: first, the need to avoid intrusion by the Executive or Judiciary into the affairs of a coequal branch, and second, the desire to protect legislative independence. Eastland v. United States Servicemen's Fund, 421 U. S. 491, 502–503 (1975). Cases considering the Speech or Debate Clause have frequently arisen in the context of a federal criminal prosecution of a Member of Congress and have therefore accented the first rationale. Only recently in such a case, we re-emphasized that a central purpose of the Clause is "to preserve the constitutional structure of separate, coequal, and independent branches of government. The English and American history of the privilege suggests that any lesser standard would risk intrusion by the Executive and the Judiciary into the sphere of protected legislative activities." United States v. Helstoski, 442 U. S., at 491. Accord, United States v. Johnson, supra, at 180-181. The Framers viewed the speech or debate privilege as fundamental to the system of checks and balances. 8 The Works of Thomas Jefferson 322 (Ford ed. 1904); 1 The Works of James Wilson 421 (R. McCloskey ed. 1967). The first rationale, resting solely on the separation of powers doctrine, gives no support to the grant of a privilege to state legislators in federal criminal prosecutions. It requires no citation of authorities for the proposition that the Federal Government has limited powers with respect to the states, unlike the unfettered authority which English monarchs exercised over the Parliament. By the same token, however, in those areas where the Constitution grants the Federal Government the power to act, the Supremacy Clause dictates that federal enactments will prevail over competing state exercises of power. Thus, under our federal structure, we do not have the struggles for power between the federal and state systems such as inspired the need for the Speech or Debate Clause as a restraint on the Federal Executive to protect federal legislators. Apart from the separation of powers doctrine, it is also suggested that principles of comity require the extension of a speech or debate type privilege to state legislators in federal criminal prosecutions. However, as we have noted, federal interference in the state legislative process is not on the same constitutional footing with the interference of one branch of the Federal Government in the affairs of a coequal branch. Baker v. Carr, 369 U. S. 186, 210 (1962). Cf. Dombrowski v. Pfister, 380 U. S. 479, 489-492 (1965) (federal court may enjoin state-court application of a clearly unconstitutional statute). Our opinion in National League of Cities v. Usery, 426 U. S. 833 (1976), is not to the contrary. There, we held that a federal statute regulating the wages of state 9 Compare Powell v. McCormack, 395 U. S. 486 (1969) (suit for injunction against individual Members of Congress to require the seating of Representative Adam Clayton Powell barred by the Speech or Debate Clause), with Bond v. Floyd, 385 U. S. 116 (1966) (individual state legislators enjoined from depriving Julian Bond of his seat in the Georgia Legislature). employees was unconstitutional because it "operate [d] to directly displace the States' freedom to structure integral operations in areas of traditional governmental functions." Id., at 852. The absence of a judicially created evidentiary privilege for state legislators is not, however, comparable intervention by the Federal Government into essential state functions. First, Gillock's argument, resting on the Tenth Amendment, has no special force with regard to state legislators; on the rationale advanced, state executive officers and members of the state judiciary would have equally plausible claims that the denial of an evidentiary privilege to them resulted in a direct federal impact on traditional state governmental functions. Moreover, we recognized in National League of Cities that the regulation by Congress under the Commerce Clause of individuals is quite different from legislation which directly regulates the internal functions of states. Id., at 840-841. Although the lack of an evidentiary privilege for a state legislator might conceivably influence his conduct while in the legislature, it is not in any sense analogous to the direct regulation imposed by the federal wage-fixing legislation in National League of Cities. The second rationale underlying the Speech or Debate Clause is the need to insure legislative independence. Gillock relies heavily on Tenney v. Brandhove, 341 U. S. 367 (1951), where this Court was cognizant of the potential for disruption of the state legislative process. The issue there, however, was whether state legislators were immune from civil suits for alleged violations of civil rights under 42 U. S. C. § 1983. The claim was made by a private individual who alleged that a state legislative committee hearing was conducted to prevent him from exercising his First Amendment rights. The Court surveyed the history of the speech or debate privilege from its roots in the British parliamentary experience through its adoption in our own Federal Constitu tion. In light of these "presuppositions of our political history," 341 U. S., at 372, the Court stated: "We cannot believe that Congress-itself a staunch advocate of legislative freedom-would impinge on a tradition so well grounded in history and reason by covert inclusion in the general language [of § 1983] before us." Id., at 376. Accordingly, the Court held that a state legislator's commonlaw absolute immunity from civil suit survived the passage of the Civil Rights Act of 1871.10 Although Tenney reflects this Court's sensitivity to interference with the functioning of state legislators, we do not read that opinion as broadly as Gillock would have us. First, Tenney was a civil action brought by a private plaintiff to vindicate private rights. Moreover, the cases in this Court which have recognized an immunity from civil suit for state officials have presumed the existence of federal criminal liability as a restraining factor on the conduct of state officials. As recently as O'Shea v. Littleton, 414 U. S. 488 (1974), we stated: "Whatever may be the case with respect to civil liability 10 Despite the frequent invocation of the federal Speech or Debate Clause in Tenney, the Court has made clear that the holding was grounded on its interpretation of federal common law, not on the Speech or Debate Clause. See Lake Country Estates, Inc. v. Tahoe Regional Planning Agency, 440 U. S., at 404. Accord, Imbler v. Pachtman, 424 U. S. 409, 429 (1976); Scheuer v. Rhodes, 416 U. S. 232 (1974). Thus, in protecting the independence of state legislators, Tenney and subsequent cases on official immunity have drawn the line at civil actions.11 We conclude, therefore, that although principles of comity command careful consideration, our cases disclose that where important federal interests are at stake, as in the enforcement of federal criminal statutes, comity yields. We recognize that denial of a privilege to a state legislator may have some minimal impact on the exercise of his legislative function; however, similar arguments made to support a claim of Executive privilege were found wanting in United States v. Nixon, 418 U. S. 683 (1974), when balanced against the need of enforcing federal criminal statutes. There, the genuine risk of inhibiting candor in the internal exchanges at the highest levels of the Executive Branch was held insufficient to justify denying judicial power to secure all relevant evidence in a criminal proceeding. See also United States v. Burr, 25 F. Cas. 187 (No. 14,694) (CC Va. 1807). Here, we believe that recognition of an evidentiary privilege for state legislators for their legislative acts would impair the legitimate interest of the Federal Government in enforcing its criminal statutes with only speculative benefit to the state legislative process.12 11 Federal prosecutions of state and local officials, including state legislators, using evidence of their official acts are not infrequent. See, e. g., United States v. Rabbitt, 583 F. 2d 1014 (CA8 1978), cert. denied, 439 U. S. 1116 (1979); United States v. Mazzei, 521 F. 2d 639 (CA3), cert. denied, 423 U. S. 1014 (1975); United States v. Homer, 411 F. Supp. 972 (WD Pa. 1976). See also Anderson v. United States, 417 U. S. 211, 214-215 (1974). Of course, even a Member of Congress would not be immune under the federal Speech or Debate Clause from prosecution for the acts which form the basis of the Hobbs Act, 18 U. S. C. § 1951, and RICO, 18 U. S. C. § 1962, charges here. See United States v. Helstoski, 442 U. S. 477 (1979). 12 Cf. Gravel v. United States, 408 U. S. 606, 627 (1972) ("[W]e cannot |