This article summarizes a stigma-based analysis of anti-equality marriage laws and campaigns. Three major themes are discussed. First, being denied the legal right to marry because of one's sexual orientation is an instance of stigma. Second, being the target of stigma is stressful, and the political campaigns surrounding anti-equality marriage amendments are a source of heightened stress for lesbians, gay men, and bisexuals. Third, structural and individual manifestations of sexual stigma are interrelated; the initial enactment and continuing existence of anti-equality marriage laws depend on the opinions and actions of the voting public. Social psychological knowledge can be useful for understanding heterosexuals’ attitudes toward those laws. Building on findings from studies of prejudice and intergroup contact, suggestions are offered for future research on how individuals influence the opinions of their family and friends about marriage equality.