United States Civil Service Commission v. National Association of Letter Carriers, 413 U.S. 548 (1973), is a ruling by the United States Supreme Court which held that the Hatch Act of 1939 does not violate the First Amendment, and its implementing regulations are not unconstitutionally vague and overbroad. Background In 1939, the United States Congress passed the Hatch Act, which barred federal employees from taking part in political campaigns. In United Public Workers v. Mitchell, 330 U.S. 75 (1947), the U.S. Supreme Court had held that the Act did not violate the First, Fifth, Ninth, or Tenth amendments to U.S. Constitution. The same day, in Oklahoma v. United States Civil Service Commission, 330 U.S. 127 (1947), the Court rejected a similar Tenth Amendment challenge to the Act. In 1971, six federal employees, the National Association of Letter Carriers, and six local Democratic and Republican political committees sought an injunction against the enforcement of the Hatch Act on the grounds that the law violated their First Amendment rights and was unconstitutionally vague. The United States District Court for the District of Columbia ruled that United Public Workers v. Mitchell had left the constitutionality of the term "political activity" open to question. The District Court then found that the term was impermissibly vague and overbroad. The District Court then argued that, even if United Public Workers had foreclosed any discussion of the constitutionality of the term, subsequent Supreme Court decisions regarding the rights of federal workers had undermined the decision and left the door open for the District Court to re-examine the Act's constitutionality. The federal government appealed to the U.S. Supreme Court, which granted certiorari. Decision Majority opinion Associate Justice Byron White wrote the decision for the majority. Justice White began by noting that while the plaintiffs in United Public Workers had only made vague assertions of the kind of political activity they wished to engage in, the plaintiffs in the present case had clearly outlined the activities they believed were unconstitutionally barred by the Hatch Act. White then "unhesitatingly reaffirm[ed] the Mitchell holding". White reviewed the lengthy history in the U.S. of barring political activity by federal workers, a practice which extended to the presidency of Thomas Jefferson, and emphasized the considered and lengthy history of the conclusion that such activity was highly dangerous to the proper functioning of government and democracy. But, citing Pickering v. Board of Education, 391