Alito’s dissent:

Today’s decision usurps the constitutional right of the people to decide whether to keep or alter the traditional understanding of marriage. The decision will also have other important consequences. It will be used to vilify Americans who are unwilling to assent to the new orthodoxy. In the course of its opinion, the majority compares traditional marriage laws to laws that denied equal treatment for African-Americans and women. E.g., ante, at 11–13. The implications of this analogy will be exploited by those who are determined to stamp out every vestige of dissent.

Perhaps recognizing how its reasoning may be used, the majority attempts, toward the end of its opinion, to reas­sure those who oppose same-sex marriage that their rights of conscience will be protected. Ante, at 26–27. We will soon see whether this proves to be true. I assume that those who cling to old beliefs will be able to whisper their thoughts in the recesses of their homes, but if they repeat those views in public, they will risk being labeled as bigots and treated as such by governments, employers, and schools.

The system of federalism established by our Constitu­tion provides a way for people with different beliefs to live together in a single nation. If the issue of same-sex mar­riage had been left to the people of the States, it is likely that some States would recognize same-sex marriage and others would not. It is also possible that some States would tie recognition to protection for conscience rights. The majority today makes that impossible. By imposing its own views on the entire country, the majority facili­tates the marginalization of the many Americans who have traditional ideas. Recalling the harsh treatment of gays and lesbians in the past, some may think that turn- about is fair play. But if that sentiment prevails, the Nation will experience bitter and lasting wounds.