Based on the basic theory of morality, this study draws on moral foundation dictionary of and other text mining tools to analyze the rhetorical clusters surrounding texts against same-sex marriage by the Coalition for the Happiness of our Next Generation. Analyses show that the Coalition adopts basic moral principles, but stresses the importance of “loyalty” and “authority” to form its own set of “discursive formation” emphasizing that the "natural marriage" system is essential to the survival of a society and that monogamy should not be challenged. Although the Coalition claims to protect basic rights of the gay community, it opposes sexual liberation initiatives that are proposed by gay rights groups, and equates sexual liberation with gay marriage, claiming that same-sex marriage can threaten the happiness of future generations. In addition, the Coalition accuses gay rights groups of taking advantage of human rights issues, and of reverse discrimination against the majority of the population. It demands to be respected for its freedom of choice against same-sex marriage. This study suggests that by understanding the basic moral foundation theory principles held by anti-gay marriage groups, the cultural war on same-sex marriage can be better negotiated, leading to improvements in subsequent communication and the implementation of gender equality policies.