The federal regulation of lobbying act of 1946 was by the supreme court.

Upheld by the Supreme Court in the case of United States v Harriss, 347 U.S. 612. In this case, the Supreme Court held that the act was not unconstitutionally vague or unclear. However, the Court did narrow who the act applied to, specifically full time, paid lobbyists who interact directly with representatives, not just staffers.