Oh boy, it’s on:

The Supreme Court announced on Friday that it would enter the national debate over same-sex marriage, agreeing to hear a pair of cases challenging state and federal laws that define marriage to include only unions of a man and a woman.

One of the cases, from California, could establish or reject a constitutional right to same-sex marriage. Another case, from New York, challenges a federal law that requires the federal government to deny benefits to gay and lesbian couples married in states that allow such unions.

The court’s move comes against the backdrop of a rapid shift in public attitudes about same-sex marriage, with recent polls indicating that a majority of Americans support allowing such unions. After last month’s elections, the number of states authorizing same-sex marriage increased by half, to nine.

The court’s docket is now crowded with cases about the meaning of equality, with the new cases joining ones on affirmative action in higher education and the future of the Voting Rights Act of 1965. Decisions in all of those cases are expected by June.

I predict that gay marriage will be a constitutional right by this time next year. Why? Because on this divided court, it’s all going to come down to how Anthony Kennedy votes. Anthony Kennedy, who wrote the majority opinion in Lawrence, throwing out Texas’s sodomy laws, and who quoted therein from his own majority opinion in Planned Parenthood vs. Casey:

These matters, involving the most intimate and personal choices a person may make in a lifetime, choices central to personal dignity and autonomy, are central to the liberty protected by the Fourteenth Amendment. At the heart of liberty is the right to define one’s own concept of existence, of meaning, of the universe, and of the mystery of human life. Beliefs about these matters could not define the attributes of personhood were they formed under compulsion of the State.

In his Lawrence dissent, Justice Scalia zeroed in on what Justice Kennedy’s logic was going to lead to: the undermining of the basis for all morals legislation. Scalia identified the majority’s citation of that Casey passage as justification for overruling its previous decision to uphold the constitutionality of sodomy laws:

And if the Court is referring not to the holding of Casey, but to the dictum of its famed sweet-mystery-of-life passage, (” `At the heart of liberty is the right to define one’s own concept of existence, of meaning, of the universe, and of the mystery of human life” ‘): That “casts some doubt” upon either the totality of our jurisprudence or else (presumably the right answer) nothing at all. I have never heard of a law that attempted to restrict one’s “right to define” certain concepts; and if the passage calls into question the government’s power to regulate actions based on one’s self-defined “concept of existence, etc.,” it is the passage that ate the rule of law.

The constitutionality of same-sex marriage — and the future of religious liberty — hangs on Anthony Kennedy’s judgment. It should be  noted that this would have been the case even if Mitt Romney had won — and even if John McCain had won, for that matter. I think it’s pretty clear what that means — and it’s not good for traditionalists — but I could be wrong. I would be grateful if any lawyers among my readership could give me reason to think I’m wrong about how SCOTUS is likely to rule.

One way or the other, we are going to have a lot more clarity about same-sex marriage and American law at the end of this court session. Good. I think.

UPDATE: I appreciate the clarity many of you commenters are bringing to this case, regarding what SCOTUS is likely to find, and what it isn’t — I mean, regarding what’s at stake in these particular rulings, and what is not at issue. Thanks.