The bottom line is that it's hard to find a model in which you can practically administer and sustain political support for those kinds of efforts. And what makes America complicated as well is the degree to which this is not just a black/white society, and it is becoming less so every year.

It's the job, I think, of leaders to try to address peoples' real legitimate concerns and channel them in the most constructive ways possible.

We’re making new investments in the development of gasoline and diesel and jet fuel that’s actually made from a plant-like substance-algae... We could replace up to 17 percent of the oil we import for transportation with this fuel that we can grow right here in the United States.

For me, personally, the most difficult moments had to do with not just terrorist attacks, but also shootings.

We know the battle ahead will be long. But always remember that, no matter what obstacles stand in our way, nothing can stand in the way of the power of millions of voices calling for change.

We can't get to the $4 trillion in savings that we need by just cutting the 12 percent of the budget that pays for things like medical research and education funding and food inspectors and the weather service. And we can't just do it by making seniors pay more for Medicare.

My core goal is to dismantle, defeat, destroy al Qaeda and its allies that killed Americans and are still plotting to go kill Americans.