constitutional authority . . . to terminate an FBI Director and to close 1086 investigations . . . cannot constitutionally constitute obstruction of justice.” As noted above, no Department of Justice position or Supreme Court precedent directly resolved this issue. We did not find counsel’s contention, however, to accord with our reading of the Supreme Court authority addressing separation- of-powers issues. Applying the Court’s framework for analysis, we concluded that Congress can validly regulate the President’s exercise of official duties to prohibit actions motivated by a corrupt intent to obstruct justice. The limited effect on presidential power that results from that restriction would not impermissibly undermine the President’s ability to perform his Article II functions. 1. The Requirement of a Clear Statement to Apply Statutes to Presidential Conduct Does Not Limit the Obstruction Statutes Before addressing Article II issues directly, we consider one threshold statutory-construction principle that is unique to the presidency: “The principle that general statutes must be read as not applying to the President if they do not expressly apply where application would arguably limit the President’s constitutional role.” OLC, Application of 28 USC. § 458 to Presidential Appointments of Federal Judges, 19 Op. O.L.C. 350, 352 (1995). This “clear statement rule,” id., has its source in two principles: statutes should be construed to avoid serious constitutional questions, and Congress should not be assumed to have altered the constitutional separation of powers without clear assurance that it intended that result. OLC, The Constitutional Separation of Powers Between the President and Congress, 20 Op. O.L.C. 124, 178 (1996). The Supreme Court has applied that clear-statement rule in several cases. In one leading case, the Court construed the Administrative Procedure Act, 5 U.S.C. § 701 et seq., not to apply to judicial review of presidential action. Franklin v. Massachusetts, 505 U.S. 788, 800-801 (1992). The Court explained that it “would require an express statement by Congress before assuming it intended the President’s performance of his statutory duties to be reviewed for abuse of discretion.” Id. at 801. In another case, the Court interpreted the word “utilized” in the Federal Advisory Committee Act (FACA), 5 U.S.C. App., to apply only to the use of advisory committees established directly or indirectly by the government, thereby excluding the American Bar Association’s advice to the Department of Justice about federal judicial candidates. Public Citizen v. United