I don't believe in trashing my opponents. I've never run a negative ad in my life. I believe in talking about issues, sometimes fighting for the media to talk about the issues, but that's what I do, and the people will decide.

We are the only major country on earth that doesn't guarantee health care to all people as a right and yet we end up spending much more than they do, so I do believe that we have to move toward a Medicare for all, single-payer system.

The basic issue of an American society which is fair, which is providing opportunity for all, is nowadays being replaced by the correct perception that we're living in a rigged economy - where it doesn't matter how hard you worked, the result will be all the income goes to the people at the very top. It's leading to a lot of frustration and anger, and people want some fundamental changes to the way we do economics and growth.

What you don't see on television is people dying today because they can't get to a doctor and they can't afford prescription drugs. That's why they are also dying. They are dying in Iraq because they are poor and they have gone into the military because they can't afford to go to college. They're dying because they're living in communities where asthma rates are extremely high because the air is filthy. The suffering of the poor and working class people is a virtual nonissue for the media. But that is the reality.

There are a lot of smart honest, progressive people who I think can be good presidents.

When we talk about power, we talk about Wall Street.

The good news is that we've seen in recent years significant reductions in the cost of solar panels and wind production. We know how significant an impact we can have by moving towards energy efficiency and transforming our transportation system. So we know what has to be done. We have to develop the political will to do it, and, as president, this would be an issue of huge concern to me.