“Anti-miscegenation” laws made marriage or sex between black and white partners a criminal act in the United States since before the United States was founded. For nearly 300 years, that was just the way things were. “Marriage” was a union between a man and a woman of the same race. For generations, everyone knew that was the definition.

Then in 1948, it all began to change. Public opinion was still vastly in favor of the anti-miscegenation laws, yet over the next twenty years, the laws were challenged and repealed on a state-by-state basis. Conservatives in both parties railed against this movement, arguing it would damage the institution of marriage, lead to the mongrelization of America and destroy traditional values… whatever those are. Slowly, gradually – when interracial marriages didn’t cause the sky to fall – public opinion reversed itself.

The United States Supreme Court usually has one eye on the Constitution, and one eye on history; and it tends to try to be on the correct side of both. When lower courts began to determine that anti-miscegenation laws were unconstitutional, AND opinion polls showed a steady, irreversible march toward acceptance, the Court decided to hear a case that would give it a chance to put its stamp on history. Loving v. Virginia ended the legal debate for good.

We’re seeing the same thing happen now with anti-gay marriage laws. Just a decade ago, few were talking about extending marriage rights to gay people. Most Americans believed that marriage was obviously between a man and a woman. But then in 2004, something happened in San Francisco: Mayor Gavin Newsom (now CA Lieutenant Governor) directed the city clerk to begin issuing marriage licenses to gay couples. This was short-lived, because even in “liberal” California, the public was overwhelmingly against extending equal marriage rights to gay people. A movement began to create a constitutional amendment prohibiting gay marriage. It took four years before that movement succeeded.

In the meantime, state after state rushed to put similar measures on their ballots in time for the 2004 election. Those ballot initiatives drew so many panicked conservatives to the polls that they gave a second term to a conservative president who at first seemed likely to lose. Yet as soon as the anti-gay-marriage movement seemed triumphant, their victories began to fade. Less than ten years later, 18 states have legalized either marriage or civil unions for gay people. Some through court rulings, others through legislation.

Time is putting an end to the moral debate over interracial marriage. In 1959, only four percent of Americans approved of marriage between blacks and whites. In 2013, 87% approve. Loving v. Virginia put an end to that legal debate.

Time is putting an end to the moral debate over “gay marriage” (the vast majority of younger Americans have no problem with it). It’s only a matter of time until the Supreme Court decides to hear an analogue to “Loving v. Virginia” that will allow it to put an end to this legal debate.