Cuba is actually one where I am more optimistic because of the unique nature of Cuba - 90 miles off our shore with a massive ex-patriot population, now Cuban-American population that still have deep links to the island. There I am more confident that over time that the winds of commerce and telecommunication and travel start shifting the nature of that regime. But that's a small country which has almost a unique relationship to us.

I think that whenever you have got an incoming president of the other side it takes a while for people to reconcile themselves with that new reality.

In the United States, if 43 percent of eligible voters do not vote, then democracy is weakened.

Change will not come if we wait for some other person or some other time. We are the ones we've been waiting for. We are the change that we seek.

As a nuclear power - as the only nuclear power to have used a nuclear weapon - the United States has a moral responsibility to act.

What makes America exceptional are the bonds that hold together the most diverse nation on earth.

The thing that has disturbed me most about the Russian hacking episode is - and the thing that surprised me most has not been the fact of Russian hacking. The cyber world is full of information gathering, you know, propaganda, et cetera. I have been concerned about the degree to which, in some circles, you've seen people suggest that Vladimir Putin has more credibility than the U.S. government. I think that's something new.