Bernie Sanders, U.S. senator from Vermont and the longest-serving independent in Congress, ran for president in 2016. His latest book, “Where We Go From Here,” was released in November.

One criticism people have is that you’re sort of a lone-wolf candidate — not a go-along, get-along-with-the-party type — and for that reason wouldn’t be able to govern. What do you say to that?

How many of those people have been to 13 states in the last month supporting Democratic candidates? I just came back from running all over the country. And I went to 30 states for Clinton. I knocked my brains out. I think where the problems come is that I often support candidates that the Democratic establishment does not, so the Democratic establishment doesn’t like me. But I could give you the names of dozens of people who are very happy to work with me and get my support.

You got more votes from people under 30 in the primaries than Clinton and Trump combined. That’s sort of the Holy Grail. How have you been able to capture young people’s imagination?

Got me. I don’t know. When you find out, give me a ring. When we began the campaign, I swear to you that no one sat down and said, “Okay, look, we’ve got to focus on young people.” That thought never occurred to us. We just went out, and we did what we did. Honest to God, people would really be stunned if they knew how ill-prepared we were for a major national campaign. And running against Clinton, we took on the entire — underlined — political establishment. No governor supported us. One member of the Senate. Handful of members of the House. No big-city mayors. In every single state, we had to take on the statewide Democratic Party.

But if you explain your ideas to people, to working people, great things can happen. I remember at a rally a guy comes up to me, he says, “Bernie, you know why I like you?” “Why?” “Because you treat us like we’re intelligent human beings.” That was after a speech that was probably an hour and 15 minutes about issues facing the American people, which bored the media completely. They didn’t really write about the speech. Oh, God, Bernie Sanders is giving the same: Rich are getting richer, da-da-da-da-da. But you had 10,000 people there, paying attention, listening. There is a hunger in this country for people to tell the truth about what’s going on. Not just in cheap rhetoric or 140-[character] tweets. People want to know why we are where we are. And we did that. People said, Thank you. You’re treating us intelligently. We appreciate that. Young people, maybe, especially.

You’ve talked about the influence of the wealthy in politics. Given how heavily weighted politics are in that direction, did you ever think you’d get this far?

The answer is capital N, capital O, underlined and bolded. No. If my parents were alive today … I mean, in the Senate, you hang out with certain types of people. Some from the upper class whose parents tell them, train them, send them to private schools; they’re groomed to be president of the United States. In the back of their minds, there is the belief they could be president. The idea that I would be a United States senator, let alone a candidate for president of the United States, would have been absolutely unthinkable in the house that I grew up in.

What is some advice you share?

I was just in Arizona at a small meeting with mostly Latino kids, activists. And some kid asked me, "What advice would you give people who are going to be out canvassing, knocking on doors?"

I said, "Look, you're going to be very nervous. But just keep pushing." In Vermont, we have mayoral elections in March. So that means you got to campaign in January and February. Pretty cold. I would literally knock on doors and be sweating. Because it's scary. You know, Who is this guy knocking on the door? But it becomes easier. And it often turns out to be a good experience. You get blown away by the intelligence of people. Where you would least expect it. Like, many years ago, I was at a county fair. People come in from the sticks — very, very rural. And this guy, who hadn't shaved in a week, came up to me — very rednecky-type guy. He says, "You one of those guys that supports gay marriage?" I thought, Oh, God, here we go. I said, "Yeah, I do." And he said, "Good! My sister's gay."

What do people tend to misunderstand or not expect about you?

Well, that I am taller than they think. Television makes you short and fat. That's number one. And I think the word "socialism" gets people a little bit nervous if they don't know what we mean by that. Three years ago, when we started talking about an agenda that worked for working families and not just the 1 percent, time and again, we were attacked, not just by Hillary Clinton, but by editorial writers all over this country that we were way, way out of touch with where the American people are, that our ideas are extreme, radical, fringe ideas.

If you look at the polling today, virtually every idea that we campaigned on has strong majority support. So, I'm very proud that taking those ideas all over this country, winning over 13 million votes and winning 22 states, made people aware that these ideas are not radical ideas, but the direction that we should be going. I think the American people are far less divided on what they want to see for the future of this country than many perceive. The reason that people like Trump can win elections is they understand there's a lot of pain out there. And for too long, the Democratic Party has not recognized that pain. But people are hurting. Five blocks away, there are moms who cannot afford to find decent-quality child care in the city of Burlington. Just a fact. Okay? And we have to talk about those issues.

In your book, you talk about colleagues who are retiring with a bit of envy. Could you see doing that anytime soon?

Anybody in politics will tell you, especially in this moment, it’s a tough life. I have some good friends who said, Okay, we’ve done it 30, 40 years, and that’s enough. And I understand that. As my wife will tell you, it’s been a long time since we’ve had a vacation, which is not a good thing. But, you know, I have seven beautiful grandchildren, four kids, and I do feel a moral necessity to do what I can to make this a world in which they can live good lives. And I’m in a position where I have some influence. And, at this moment, I just cannot walk away from that.

This interview has been edited and condensed. Follow KK Ottesen on Twitter: @kkOttesen.