On your wall is the cover of a 1950s Senate report on hiring gays. The title is “Employment of Homosexuals and Other Sex Perverts in Government.” At the time you were closeted, and now you’re engaged to Jim. That’s quite a trajectory.

I will be the first same-sex married member of the US Congress. I called Massachusetts chief justice Margaret Marshall, who’s now retired, because she wrote the opinion and I thought it would be great if she married us. I left a message on her voice mail: “Margaret, will you marry me?” She called right back and said, “Oh, I would love to.” But she’s going to be out of town.

What was it like being a gay lawmaker when all these changes were happening?

I became the leader of the gay-rights movement in Massachusetts by the process of elimination. In ’72, gay groups wrote to everybody running for the legislature and said, “Will you introduce gay-rights legislation?” I was the only one who said yes. So I became their leader. I had to think: Should I do it? Will they think I’m gay or will they think, “He wouldn’t if he was.” I was terrified of being found out.

I thought if I wanted a career in politics, I’d have to conceal my sexuality. But it would have been despicable to oppose gay rights. I can’t live one way and allow other people to be penalized for it. I thought, okay, I’ll live part in, part out. That wasn’t working. The strains were terrible. I couldn’t do it. I was not able to have a healthy social and sexual life. I’m proud that I came out voluntarily.

Did you think you’d ever want to get married?

No. Ten years ago it never seemed possible, so why even think about it?

You never seemed like the marrying kind. Now you’re almost goo-goo eyed.

I’m very happy. Jimmy and I complement each other very well. We have a lot of differences, but it’s the companionship. And it’s love. How did colleagues react when you came out?

People were very supportive, very generous—including a couple of Republicans. [Former Wyoming senator] Al Simpson called me and said, “Barney I am so embarrassed. I think I may have made a couple of anti-gay jokes when I was around you. And I feel so terrible—I admire you so much.” I was in Roland’s, the convenience store, shortly after I had come out, and [former New Hampshire senator] Warren Rudman was leaving, and quite deliberately he said, across the length of the store, “Hey, Barney, I’m proud of you.”

If I weren’t gay, I might have tried to get into leadership. I don’t know how it would have worked out. I do believe if John Kerry had been elected President I probably would have won his Senate seat.

But you don’t think you could have been in leadership as a gay man?

No, I don’t. But I became the ranking member of this important committee, and nobody voted against me. We have a secret ballot. And then I get to be the chairman of that committee, and because of the financial crisis, I become one of the most important members of Congress—not personally, just institutionally. The fact that I was gay was of zero impact.

Did the Gobie episode lead you to reassess things?

I felt terrible about it, but fortunately I had come out beforehand. If that was the occasion of my coming-out, it would have been bad. And my colleagues were very generous. Shortly after that, [then-California congressman] Leon Panetta called me. He wanted me to be on the Budget Committee.

Some people thought that when you became chairman of Financial Services, you’d act more like Chairman Mao. Do you think you surprised them?

I’ve always been a free-market guy. I think you can make the free market work for liberal purposes. I want to make the capitalist system work and take a good chunk of that money and provide for the disadvantaged.

You’ve been blamed for the mortgage meltdown. Why do you think that was?

This was a crisis of non-regulation. Republicans tried to prove it wasn’t that the private sector was under-regulated by the federal government but that the federal government made the private sector do bad things. They needed to shift the blame for the crisis from the irresponsibility of the financial sector and the absence of government regulation to saying the government made everybody do it. It was not a theory that had much economic support. But that’s why I became the culprit.

But was it partly your fault? Are there things you would have done differently?

I underestimated how bad the housing crisis would be. But I’ve been critical of mortgages for very poor people. I’ve been saying for a long time, no, rent them housing. Up to 2003, I was too resistant to more regulation of Fannie Mae and Freddie Mac, but in the area where they got into the worst trouble, I was for more regulation.

Also, I was in the minority. All this bad stuff happened before [former senator] Chris Dodd and I became the chairs.

You supported Hillary Clinton’s presidential campaign in 2008. How’s President Obama doing?

I’ve been very happy with him, but he overestimated his ability to charm the savage beast. He said he was going to be post-partisan. Knowing how far right the Republicans are, I said that he was giving me post-partisan depression. I think he made a mistake by being too conciliatory at first.

What was your reaction to the President’s endorsement of gay marriage?

I was happy. But for me, the big moment was when he came out against DOMA [the Defense of Marriage Act, which says no state is required to recognize gay marriages performed in other states]. It has much more of a federal impact. And once he said that, it was clear he was going to have to come out for gay marriage.

Now that you’re leaving, are there things you’re disappointed you weren’t able to get done?

The biggest is rental housing. We didn’t get a low-income-housing trust fund established. The other is the Employment Non-Discrimination bill [to prohibit discrimination by civilian, non-religious employers on the basis of sexual or gender identification]. I really think we could have had an Employment Non-Discrimination Act if we hadn’t included the transgender issue. I think we should include it, but it would have been better to do it in two steps.

Your partner, Jim, got a hug from the President at the inauguration, right? And you took a picture of it up to the White House for Obama to sign. What did he write?

“Sending you love for keeping Barney under control.”

Are you going to miss this place?

Parts of it.

With that, Frank said, “Okay, I gotta go,” and picked up the phone again. I stuck out my hand to shake his, and he looked at it as if it were a two-headed fish.

“Bye, Barney,” I said.

“Oh,” he said. “I’ll be around awhile.”