In March 2017, the U.S. Supreme Court decided "Friedrichs v. California Teachers Association," a case addressing the constitutionality of "agency fees" for non-union teachers in California. Although the Court's 4-4 decision in the wake of Justice Scalia's death upheld the constitutionality of agency fees, several similar lawsuits have been filed since then, with the hope that a nine-member Supreme Court will issue a different decision. Using legal, historical, and empirical analyses, we examine "Friedrichs" as part of the broad-based effort to weaken public sector unions generally and teachers unions in particular, and we assess the likely effectiveness of cases like "Friedrichs," both in the legal arena and as part of a strategy for improving teacher effectiveness.