In the campaign back in 2007, 2008, people would say, "Oh, he's being naïve. He thinks that there's no red states and blue states. And wait 'til he gets here." And I will confess that, I didn't fully appreciate the ways in which individual senators or members of Congress now are pushed to the extremes by their voter bases. I did not expect, particularly in the midst of crisis, just how severe that partisanship would be.

The president and the executive branch are always going to have greater latitude and greater authority when it comes to protecting America because sometimes you just have to respond quickly and not everything that is a danger can be publicized and be subject to open debate, but there have to be some guardrails.

Nothing can stand in the way of the power of millions of voices calling for change.

Global warming is not just the greatest environmental challenge facing our planet - it is one of our greatest challenges of any kind.

I think sometimes Europe may take for granted the extraordinary progress that's been made over the last 40, 50 years. I recognize that sometimes there is great frustration that arises out of the euro zone or out of the EU.

I need you to go out and talk to your friends and talk to your neighbors. I want you to talk to them whether they are independent or whether they are Republican. I want you to argue with them and get in their face.

Look, Americans will go for leadership that makes sense. Our job, you know, as public officials, is not to put our finger in the air. Our job is to listen, and then lead.