A political candidacy built around hope and change and compromise would eventually become a presidency of crisis and confrontation.

What makes [cyber security] difficult is because it's not just a government problem. It is a private sector and government problem. And there's gotta be a lot more cooperation.

All of us take offense to anyone who reaps the rewards of living in America without taking on the responsibilities of living in America. And undocumented immigrants who desperately want to embrace those responsibilities see little option but to remain in the shadows, or risk their families being torn apart.

People are less certain of their national identities or their place in the world. It starts looking different and disorienting. And there is no doubt that that has produced populist movements both from the left and from the right in many countries in Europe.

Internationally, I have obviously been deeply concerned about how we fight the terrorist threat.

We remain a young nation, but in the words of Scripture, the time has come to set aside childish things. The time has come to reaffirm our enduring spirit; to choose our better history; to carry forward that precious gift, that noble idea, passed on from generation to generation: the God-given promise that all are equal, all are free, and all deserve a chance to pursue their full measure of happiness.

For the first time, preventing nuclear proliferation and nuclear terrorism is now at the top of America's nuclear agenda.