We can't rely - or no country can rely on just a single personality to carry it forward. And so what the American founding fathers understood was that institutions were built for human imperfection not human perfection.

Leading in a complex world means recognizing the simple things you can do to make things better.

After all, when the world looks to America, they look to us because we are the most successful political and economic experiment in human history.

Power is nothing unless you can turn it into influence.

I'm very proud that President [George W.] Bush took on AIDS relief. It was the largest single response by any country to a major international health crisis, and there are millions of people who are alive today in Africa and other developing countries because of that program.

I was born in segregated Birmingham, Alabama. I didn't have a white classmate till we moved to Denver.

I think it's very humble to believe that there is no man, woman or child who should live in tyranny. That people who say, well, maybe Arabs just aren't ready for democracy or maybe Africans just are going to have corrupt governments, that seems to me arrogant.