In 1993, the US Congress eliminated funding for the Superconducting Super Collider (SSC). The audacious particle accelerator project, had it been built, would have been the world’s largest scientific instrument, securing US dominance in high-energy physics for years to come. Why, then, did both policymakers and the American public sour on the project in the early 1990s? Historians have proposed a number of reasons, ranging from internal mismanagement and cost overruns to the end of the Cold War and the shift in national priorities that accompanied it. This talk will explore those explanations in light of another, less appreciated factor: the vocal and public opposition condensed matter physicists and materials scientists mounted against the project. The fight over the fate of the SSC was a fight over the future of physics, and examining resistance to the project from within the physics community sustains a comprehensive assessment of what the SSC’s demise portended for physics as the twentieth century drew to a close.