In ongoing efforts to understand the exceptionalism of the American labor movement, historians have proposed a reason why American unions never fully embraced the independent and social democratic politics of their European counterparts: a hostile legal system, they argue, fostered a deep distrust of state intervention among early labor leaders. Thomas Clark joins revisionists in questioning this apolitical and antistatist characterization of the early labor movement, but from a new perspective. By focusing on law and labor activity at the state level rather than the national level and using California as his case study, Clark shows how legal hostility pushed labor into politics on a local level with greater urgency and failed to compel labor to oppose state intervention more generally. Focusing on California provides Clark a unique opportunity to investigate the law's impact in two different settings - closed shop San Francisco and open shop Los Angeles - within the parameters of a single state legal system. Clark describes how local court and police hostility pushed labor into periodic experiments with third-party politics, and, as in San Francisco, sometimes helped lab