The federal same-sex marriage decision out of California sets into motion a sequence of events that will result in a Supreme Court earthquake two years from now. The Supreme Court can either vindicate traditional marriage, or forever redefine the most basic unit of human civilization.

Sounds melodramatic, but unfortunately — it’s true.

On August 4, the U.S. District Court for the Northern District of California decided Perry v. Schwarzenegger. The voters of California amended the California Constitution to say marriage in California is between a man and a woman. In Perry, the issue was whether there is a federal constitutional right to same-sex marriage, such that any state law, federal law, or state constitution to the contrary is unconstitutional.

The U.S. Supreme Court has held that marriage is a fundamental right in the U.S. Constitution. In this ruling, Chief Judge Vaughn Walker held that the California Constitution violates that federal right by not allowing gays to marry each other.

Although not explicitly mentioned in the Constitution, marriage is an implied fundamental right. The test for whether a right is a fundamental right is whether it is rooted in the history and tradition of the American people, and essential to an Anglo-American scheme of ordered liberty.

No one in this lawsuit disputes that the right to marry fits those two criteria of being rooted in our history and essential to an American concept of ordered liberty. So the question is whether same-sex marriage also meets that test.

The judge’s mistake ultimately comes from a false choice he sets up as the legal issue. He writes, “The question presented here is whether plaintiffs seek to exercise the fundamental right to marry; or, because they are couples of the same sex, whether they seek recognition of a new right.”

That’s not the issue. The issue is whether a person has the right to redefine marriage. The district court tried to deal with that issue by declaring its own definition of marriage: “Marriage requires two parties to give their free consent to form a relationship, which then forms the foundation of a household.”

One of the problems with that definition is the word “two.” Why only two? Dozens of countries across the world practice polygamy, where a man can have more than one wife. Islam, for example, permits a man to have four wives, and that’s the law in Muslim nations. Why does the court insist on two?

There are other problems as well. In many countries, a person can be married at an age that is considered too young in America to give consent. In others, consent is not required regardless of age; many women are forced to marry against their wishes. In some cultures, people can marry close relatives, and in a few over time, even brothers and sisters.

None of that is protected by our Constitution. American laws against polygamy, child-marriage and incest do not run afoul of the Constitution.

But the federal judge in this case chose to define marriage in such a way that it would give a green light to same-sex marriage, while not casting into doubt all of these other laws that ban all of these other types of marriage.

The problem for the district court is that same-sex marriage shares the same problem as all those others when it comes to the constitutional test: None of them are found in the history and tradition of the American people. And none of those types of marriage have been found essential to an American concept of liberty. Therefore none of them are part of the fundamental right of marriage.

In the end, the Constitution protects the fundamental right for one man and one woman to get married, so long as they are not close relatives. That’s why laws that don’t allow interracial marriage are unconstitutional, but a law saying that a man cannot marry another man is not unconstitutional.

This case showcases some of the best legal talent in America. Supporters of same-sex marriage are represented by liberal legal legend David Bioes and libertarian/conservative Ted Olson, who is probably the most successful Supreme Court lawyer alive today. In a gross dereliction of duty and betrayal of their oaths of office, California state officials are not defending California’s state constitution in this challenge. So supporters of traditional marriage are being represented by conservative legal icon Charles Cooper—who was Ronald Reagan’s top legal advisor under Attorney General Ed Meese, and a former law clerk to late Chief Justice William Rehnquist.

These legal heavyweights will continue to fight this out. The Perry case goes now to the U.S. Court of Appeals for the Ninth Circuit, where the odds are good that the appellate court will affirm the trial court. (Most of the judges on the Ninth Circuit—which is the most liberal federal appeals court in the country—are either liberal or libertarian.) From there, it will go on to the U.S. Supreme Court.

This case parallels another case out of Massachusetts, where a few weeks ago a federal judge held the federal Defense of Marriage Act unconstitutional. That case is now on appeal to the U.S. Court of Appeals for the First Circuit.

So the issue of same-sex marriage is moving up the federal court system on two tracks. The odds are good that they will end up before the Supreme Court at the same time, and the odds are very good that one—or both—will be decided in the first half of 2012.

What position will the Obama Justice Department take as these cases go to the High Court? Will President Obama hold to his official statement that he believes in traditional marriage? Who is he going to alienate right at the end of his reelection campaign, his base, or swing voters?

This case presents one of the most important social issues in America’s history. As a society, we all have a vital stake in the outcome.

(Editors’ Note: this piece was co-authored by Ken Klukowski, who is special counsel with the Family Research Council and senior legal analyst with the American Civil Rights Union, and coauthor of The Blueprint: Obama’s Plan to Subvert the Constitution and Build an Imperial Presidency.)