In Marriage Matters, Janice Shaw Crouse argues that marriage is a critical element in a free society and that society's most vulnerable communities, especially minorities and the poor, suffer the most from the retreat from marriage. Because marriage advances the public interest, we should create laws and policies that support rather than undermine it. Crouse demonstrates both the public and private importance of marriage, and organizes her argument in a thoughtful and logical manner.

Crouse argues that marriage is by far the best family unit for raising children, and shows how the trend away from marriage has fuelled some of the nation's worst social problems. Households lacking traditional fathers are disproportionately poor. Crouse notes the government has taken on a breadwinner role by creating welfare programs such as food stamps and Medicaid, but observes that social programs cannot provide the moral guidance of a father.

The groundwork for strong marriages and lasting relationships is examined in detail. Crouse also discusses the role of sex in marriages and the harmful influence of casual sex. She shows how marriage matters to individuals (specifically to women and children) and depicts same-sex marriage as a potential threat to the institution. Other public policy issues affecting marriage are also explored.