As a distinct class of criminals, sex offenders stand out as being particularly subject to the new “risk management” penal strategies that, according to a number of scholars, have come to dominate punishment rhetoric and practices in recent years. Nonetheless, the criminal justice policymaking that targets sex offenders appears to have a more emotionally based underside. In this paper, I examine the emotional drive that appears to undergird contemporary sex offender lawmaking, suggesting that a significant force propelling the current panoply of sex offender containment strategies is a constellation of emotional expressions of disgust, fear of contagion, and pollution avoidance, manifested in a legislative concern about boundary vulnerabilities between social spheres of the pure and the dangerous. To do so, I analyze the lawmaking discourse of U. S. legislators as they debated four proposed legislative bills directed at sex offenders during the late 1990s.