The hard truth is carbon pollution has built up in our atmosphere for decades now. And even if we Americans do our part, the planet will slowly keep warming for some time to come.

Here in Europe some of the challenges have to do with structures that are so complicated. You've got Brussels, and you've got parliament, you've got councils and then you've got national governments. So people sometimes don't feel as if they know who's making decisions, and the more that we can bring people in and engage them, the better. Some of it is also cultural and social, people's sense of identity.

Together we resolve that a great nation must care for the vulnerable and protect its people from life's worst hazards and misfortune.

I think Ronald Reagan changed the trajectory of America in a way that Richard Nixon did not and in a way that Bill Clinton did not. He put us on a fundamentally different path because the country was ready for it.

I think that we've had an economy that's been out of balance for too long. So the general principle of raising taxes on higher income Americans, like myself, and providing relief to those who haven't benefited as much from this new global economy, I think is a sound one.

If I'm president, some day, young kids will look at the world differently. They will say, I could be president some day. They couldn't have said that before I came along. The world will see the United States in a different context, as a country of true opportunity for all.

If somebody is different from you, that's not something you criticize, that's something that you appreciate.