In a rare interview, posted online on Sunday, U.S. Supreme Court Justice Samuel Alito Jr. criticized the court's June 26 ruling declaring a right to same-sex marriage, warning that “we are at sea” in defining the limits of constitutional protections of liberty.

The court majority, Alito said, has adopted a “post-modern” concept of liberty protected by the 14th Amendment's due process clause. Alito described that concept as: “It's the freedom to define your understanding of the meaning of life. It's the right to self-expression.”

With that broad understanding of liberty, Alito said, a future libertarian justice could attack minimum wage and zoning laws, and a socialist justice could argue in favor of a guaranteed annual income or free college education for all.