Under OLC's analysis, Congress can permissibly criminalize ce1tain obstructive conduct by the President, such as suborning perjury, intimidating witnesses, or fabricating evidence, because those prohibitions raise no separation-of-powers questions. See Application of 28 U.S.C. § 458 to Presidential Appointments of Federal Judges, 19 Op. O.L.C. at 357 n.11. The Constitution does not authorize the President to engage in such conduct, and those actions would transgress the President's duty to "take Care that the Laws be faithfully executed." U.S. CONST. ART IT, §§ 3. In view of those clearly permissible applications of the obstruction statutes to the President, Franklin's holding that the President is entirely excluded from a statute absent a clear statement would not apply in this context.
Since the DoJ won't indict a sitting president, here's a direct suggestion of what Congress could do.
