Get ready for more gay rights made possible by a Catholic judge

Can you feel it? There was a bit of a bump there.

This week’s Supreme Court decision overturned part of a federal same-sex marriage statute.

But more importantly, it shifted the law of the land, changing the way courts must view countless millions of gay and lesbian Americans.

Lawyers call it U.S. versus Windsor, but history teachers likely will call it groundbreaking – like Brown versus Board of Education of Topeka, which ended racial segregation – or Roe versus Wade, which ended the ban on abortions.

Now, legal same-sex marriages will likely spread to other states, experts say. The rulings open the door to future Supreme Court decisions about related issues such as divorce and child custody.

This historic event also underscores the idea that, sometimes, one person really can change history.

The vote count to overturn the law, called the Defense of Marriage Act, aka DOMA, was 5-4.

Read more about the court’s decision

Who was the Supreme Court justice who cast the key swing vote that tipped the total in favor of gay rights? Anthony Kennedy.

Perhaps some might be surprised to learn that Kennedy is not what you might call a “liberal judge.”

CNN Senior Legal Analyst Jeffery Toobin has spent much time with Kennedy over the years – writing extensively about this Reagan-appointed, observant Catholic justice from a Republican family.

Toobin spoke with us to help put the whole thing into a broader perspective – shedding light on Kennedy’s legacy and on the future of gay rights.

Toobin: Fortunately for Kennedy he has many important opinions to his name. But I do think it’s clear that his identification with gay rights will be in the first paragraph of his obituary, years down the road. He will be remembered as the justice who brought gay rights into the Constitution.

The Supreme Court has had three major gay rights decisions in its entire history. And Anthony Kennedy wrote all three of them.

That’s the kind of identification with an issue that is almost unprecedented in the history of the court. The three cases are Romer versus Evans in 1996, Lawrence versus Texas in 2003 – and now U.S. versus Windsor.

There will certainly be more gay rights Supreme Court cases. The issue of what rights gay people have in states that don’t have same-sex marriages is going to come before the court more and more.

Also likely to come before the court is this sort of issue: if two men get married in Massachusetts and move to Alabama, how do they get divorced and who gets custody and visitation of their children?

And this one: Now that DOMA’s gone, what happens to the federal benefits for married couples who move to states that do not protect gay rights? Those are very difficult questions that will now be before the court.

CNN: Were you surprised at Kennedy’s decision?

Toobin: I was not surprised that Kennedy voted to overturn DOMA. I was surprised at the expansiveness of his language and the fullness of his embrace for equal protection for gay people.

His opinions certainly invite the claim that every state in the union has to offer gay people the right to get married. It doesn’t say that. But one could certainly argue that the logical implication of his holding is that every state in the union has to have same-sex marriage.

When the United States Supreme Court says that gay people need to be treated equally, that reverberates not just around the country, but around the world. We have not been the leading country in protection of gay rights. But we are still the most powerful and most looked-to country in the world, and this decision will reverberate worldwide.

For a decade – and perhaps longer – Kennedy has been the most influential justice on the court. And he has the opinions – both liberal and conservative – to prove it. There are four reliable liberals and four reliable conservatives on the nine-member Supreme Court. And in many cases, his vote is the only one usually in play.

The justices all have clear approaches to the Constitution. And that leads them to reach legal conclusions in predictable ways. Kennedy is perhaps the least predictable and in an evenly divided court, that gives him enormous power.

People shouldn’t get the impression from this opinion that Anthony Kennedy is a liberal justice. His most famous opinion is Citizens United, which is reviled by liberals as an invitation to corruption and money in politics. So he’s not just some outspoken liberal.

Anthony Kennedy is personally very conservative and very conventional. He is an observant Catholic from a Republican family in Sacramento, California.

CNN: Will Kennedy’s opinion about gay rights influence the other conservative Supreme Court justices?

Toobin: I think the idea of justices influencing each other is mostly a myth. They think what they think. They are all highly intelligent, opinionated people who have given a great deal of thought to the Constitution and lobbying from their colleagues rarely changes their mind. But that makes Kennedy’s position all the more important, because he’s the one who finds himself sometimes allying with the liberals, but mostly with the conservatives.

He is very family oriented and not someone who seems buffeted by changes in the broader world.

But he’s obviously a man of broad interests.

Justice Kennedy has a great interest in international law and he used to go to Salzburg, Austria, to teach every summer. In the mid-2000s, I went with him to Salzburg and interviewed him there. It’s funny, when he was nominated to the Supreme Court in 1987, he still lived in the house in Sacramento where he grew up. But throughout his life, he has had this incredible wanderlust. He has traveled all over the world – he still does – and the summers in Salzburg reflect that. We had a whole bunch of time together.

CNN: Where does Kennedy rank now historically among other Supreme Court justices?

Toobin: Well he certainly belongs near the very top in terms of his influence. As for greatness, I think it’s going to take a little bit more time to measure that.

CNN: Will the court’s decision push Americans who disagree with gay rights to change their minds?

Toobin: The court often reflects the country and I think this decision does reflect at least in part the tremendous changes that are going on in the country at large about gay rights issues. And the court both reflects and adds to those changes. It’s just a dramatic, dramatic change.