Theodore “Ted” Olson has argued 59 cases before the U.S. Supreme Court, but his 60th argument has the potential to be the one for which the Gibson, Dunn & Crutcher partner will be most remembered.

In March, the court will hear Hollingsworth v. Perry, the challenge to Proposition 8, the 2008 ballot initiative that amended the California Constitution to eliminate the marriage rights of same-sex couples. Olson and his co-counsel, David Boies of Boies, Schiller & Flexner, hope to persuade the court that Prop 8 violates the U.S. Constitution.

Even supporters of marriage equality worry that it’s too soon to bring a case like Perry before the court.

Another case to be heard in tandem with Perry is considered to have better odds. In U.S. v. Windsor, advocates of marriage equality seek to overturn the section of the Defense of Marriage Act that bars the federal government from recognizing same-sex marriages performed in the states where they’re legal. In an interview, Olson explained why he thinks the time is right for his case. The interview has been edited for length.

Q: You’ve said before that you think all of the justices are potentially winnable. Justice Antonin Scalia recently made well-publicized remarks at Princeton University in which he reiterated his opposition to marriage equality. Do you still think he’s potentially winnable?

A: I’ve said it slightly differently. David and I have both said that we’re not taking any justice for granted, and we’re not writing off any justice. We’re trying to structure our arguments so that they would appeal to each and all of the justices. I’m aware of this recent controversy about Justice Scalia, and I’m also aware that it’s based upon things he’s said in dissenting opinions, which most people would say are not favorable to our side of the case. But we want to see if we can find an area where he would be comfortable with an outcome favorable to us.

Q: Scalia said that a society should be able to adopt “moral sanctions.” How would you respond to that argument?

A: It would depend on the context in which it came up, but there are findings in this case that sexual orientation is an immutable characteristic. It is not a question of violating moral standards — it is a condition that we’re are born with. I like to say that I didn’t choose to be heterosexual, and our clients have all said that they did not choose to be homosexual. So we would focus on that, to the extent that the issue of morality comes up.

Q: Several stories have discussed how you became involved with this case — director Rob Reiner was talking about a challenge to Prop 8 at a Los Angeles restaurant when a mutual acquaintance suggested he get in touch with you. What happened next?

A: Rob and his wife, Michelle, were talking about the fact that the then-pending challenge to Proposition 8 was based on the California Constitution alone. But at some point, a federal constitutional challenge was going to be brought by someone, and that that case needed to be well-structured, involving the right plaintiffs and the right lawyers, and with the right resources, so that if it was to go to the U.S. Supreme Court, it would be the right case to do so in all respects. They were talking about that, and they were overheard by my former sister-in-law, who said, “You ought to contact Ted Olson.” They expressed some skepticism, because I’m known to be a conservative. She said, “You might be surprised. Why don’t you call him?”

I think there was an email first from someone asking me whether I’d be willing to consider this, and I said I was. Then Rob Reiner’s associate, Chad Griffin, who’s now the head of the Human Rights Campaign, was tasked with giving me a call, which he did. I said I would be interested in assisting this kind of challenge, provided that it was done right with all of the right pieces in place right from the beginning.

A number of meetings followed, and at some point I expressed the view that it shouldn’t just be me and the lawyers from my firm because I didn’t want the attention to be on me but on the issue and our clients. And I thought it would be good to have someone from the opposite political party. Ultimately I decided to recommend to the group that it be David Boies. Everyone agreed that that would be a great idea. I contacted him, and he was instantly willing to do it.

Q: Why and when did marriage equality become an issue for you?

A: I had never been involved in the issue personally, but I am troubled by discrimination on the basis of sexual orientation. We all have friends or neighbors who are gay. I don’t have any family members who are gay, but many people do. We certainly have partners and associates in our law firm who are gay. An individual’s sexual orientation is not a basis in my judgment for discrimination or condemnation or ridicule or separation. These individuals are citizens and are entitled to the same rights and respect and happiness as the rest of us. I’ve felt that way for a long time.

The marriage issue is a relatively recent focus, but it is a part of equality. In a cover story for Newsweek a couple of years ago, “The Conservative Case for Gay Marriage,” I argued that marriage is a conservative value. We’re talking about individuals who wish to live together in a stable environment, who want to become part of the community. Conservatives should be in favor of that.

Q: When you’ve spoken at conservative events, has anyone come up to you afterward and said, “Well, privately, I think you’re right.”

A: It’s been a wide spectrum of reactions. Some people have come up to me and said that they strongly disagree with what I’m doing, and some of that comes over the transom in hostile emails. Many people have said, “I agree with you as a matter of what should be permitted, but I disagree as to whether it should be a constitutional right.” Some people have said, “You know, I’ve thought about it, and I agree with you.” Many people have said, “I felt differently about this until I started hearing you.”

And I’m not giving myself any sort of exclusive credit. The fact that David Boies and I have come together on this has given us an increased audience. People use the term “odd couple” — we have had an opportunity for a wider audience because of the novelty. And the more people we talk to, the more people who are willing to think about it. And the more people who people think about it, the more people who come to the conclusion that it’s just wrong to single out people for their sexual orientation. Young people, by and large, don’t even understand why it’s an issue.

Q: There are many supporters of marriage equality who think it’s too soon to go before the Supreme Court. How do you respond?

A: Everyone in California knew that somebody was going to bring this suit, and it was going to happen around the time that we did it. Those of us who practice at the U.S. Supreme Court have seen what can happen with a poorly presented case. So one of the concerns that Rob and Michelle Reiner and others expressed was that if the case was going to go to the Supreme Court, which it was inevitably, that it be done correctly.

Secondly, when you have people who are victims of discrimination — who feel that their constitutional rights are being violated — who are we, as lawyers, to tell them, “No, we won’t help you, we won’t go to court to help you vindicate your rights, you’re coming too soon”? You can’t say that to people who are suffering from discrimination and who want the assistance of lawyers to present their case on a constitutional basis in the federal courts. That’s why we have a Constitution, and that’s why we have courts.

Thirdly, we did spend a lot of time talking with groups that had some reservations about this, and they expressed those reservations to us, and we respected them. … But they couldn’t answer the question, “When would be the right time?”

Someone said to me, “Ted, you should reread Martin Luther King’s ‘Letter from a Birmingham Jail,’ in which he responded to people who said, ‘Dr. King, you’re going too fast, there’s going to be a backlash, it’s going to hurt our cause terribly.’ He wrote about why the rights of man have to be pursued, and battles have to be fought, and some battles will be lost, but ultimately the arc of history curves towards justice.