One doesn’t often hear lukewarm descriptions of Barney Frank. The 16-term Massachusetts congressman is known as brilliant, witty, and a relentless worker. He’s also cranky, verging on rude, and impatient with people who ask ill-informed or deliberately provocative questions. Divergent as these characterizations are, they are all true.

As former chairman of the House Financial Services Committee, Frank has held one of the most powerful positions in Congress. But he’s utterly unpretentious, retaining the demeanor he acquired in his Bayonne, New Jersey, birthplace and while chatting with the fishermen in his coastal New England district.

When I showed up at his office, Frank was on the phone attending to a housing matter that sounded as if it easily could have been passed off to a staffer. Next to his desk were three low tables filled with awards, etched with thanks from everything from gay-rights organizations to fishing groups.

Yet many of Frank’s detractors see him as a supervillain. He’s liberal, openly gay, and a prime target of Tea Party activists, who tried to oust him in the 2010 elections. Much of that has to do with Frank’s left-leaning views, but it’s the 72-year-old’s sexual orientation that has driven conservative animus and complicated his political career.

In 1985, he hired Stephen Gobie as an aide and engaged in a personal relationship with him. Frank fired Gobie after learning he was running a gay prostitution ring out of the congressman’s apartment. An Ethics Committee investigation cleared Frank of everything but fixing Gobie’s parking tickets and attempting to influence the terms of his probation.

When Frank entered Congress in 1981, he was in the closet. He has announced he’ll retire at the end of this term, and this month he’s marrying his partner, Jim Ready. But while Frank is a loyal supporter of gay rights, he hates being classified as “the gay congressman” when his policy interests have been focused heavily on housing, his district’s fishing industry, and finance.

After 31 years in Washington, Frank sat down to reflect on a Congress and a country that have moved, albeit slowly, toward a more tolerant view of gays and lesbians.

You’ve got power and seniority, and you survived one of the toughest races of your career in 2010, when conservative Republicans targeted you as a villain in the subprime-mortgage crisis. Why leave now?

I always figured I would serve here until I was 75. I was ready to run for one more term. But I’ve gotten tired, emotionally drained. The four years I spent as chairman of the House Financial Services Committee were very demanding. I found myself in the middle of this financial crisis with material that was intellectually difficult, politically difficult, with enormous consequences if you made a mistake. It’s kind of like driving down a curving road at a high speed.

Then the redistricting came. They changed the district so drastically that I would have been spending this year introducing myself to 325,000 new people.

And there are other things I want to do, particularly write. Pat Moynihan, who was an incredibly gifted man, was able to write serious books while he was a senator. I’m too easily distracted. I can only write if I’ve got nothing else as an excuse not to write, and I want to get out of here while I’m still sentient and able to do that.

How has Congress changed in your time here?

It has become more partisan in both good and bad ways. When I got here, you had very conservative Democrats and some liberal Republicans. I don’t think that was healthy; I do think parties should stand for something.

Then Newt Gingrich came along and had a major impact in saying this is not a debate between two groups of people of good will. This is the good guys versus the bad guys, the immoral guys, the treasonous guys, the corrupt guys. That introduced a great deal of anger. Even then, though, you could cooperate some.

Was it really all Gingrich’s fault?

No, it’s now also the nature of the media.

The media has been totally fractured, so the most active people, right and left, live in parallel media universes. They only hear what they agree with. When you try to compromise, you are not criticized because of the specifics of the compromise but because you decided to compromise at all.

Veteran senator Dick Lugar was recently ousted in his primary by a Tea Party candidate, who criticized him for selling his Indiana home and basically living in DC. What does that say about what’s happening to Congress?

First, I think Lugar’s been somewhat overpraised. For one thing, this business of voting from a house in Indiana that he sold 35 years ago and staying at a hotel when he visited—those are things that shouldn’t have been done. He gave seniority a bad name with that.

Second, he was prepared to save his seat by embracing the right wing, so it would not have been a great victory for compromise and moderation if he won.

In 2009 you were named by your GOP colleagues, surveyed by the Hill newspaper, as being among both the most partisan members of Congress and the most bipartisan. How did you manage that?

I’m very proud of that. I think that’s the way to be. Partisanship is very important. You need parties to make things work. The problem with partisanship is not that it exists and not that people divide along ideological lines, but that people have allowed differences along partisan lines to become so personally embittering that they can’t work together.

I work very hard at legislating. I enjoy it. It is the most important thing I can do because it’s a chance to make the world fairer. And I think I can show that you can make it fairer without making it less efficient. But you don’t fight in a way that makes it harder to work together.

You’ve said you hate having to be nice to people you don’t like. In your last campaign, your website had ads of you sounding like Mr. Nice Guy. Is that part of why you chose to make 2010 your last campaign?

I’ve always believed I’m a much better legislator than a candidate. I’m not a great candidate. And this campaign came upon me while I was in the midst of trying to get the financial-reform bill through. I wasn’t really able to put my mind to the campaign until July. And then I did a lousy job. I didn’t hire the right people, I lost control of it. I ran a terrible campaign.

Did you worry about losing?

I did, but I often think I’m going to lose. You have to understand, I was an ultimate outsider for much of my life because I was a closeted gay man, socially awkward, overweight.

It was never close, but I’m very insecure.

So you’re a good legislator and a bad candidate. What else?

There are a lot of things I’m terrible at. I have not handled my personal life well until a few years ago, and now I’m doing a good job with Jimmy. I’m very proud of that. He’s been a great influence.