On my recent trip to Israel, I had the opportunity to visit Yad Vashem, Israel's national Holocaust memorial, and reaffirm our collective responsibility to confront anti-Semitism, prejudice, and intolerance across the world. On this Yom Hashoah, we must accept the full responsibility of remembrance, as nations and as individuals-not simply to pledge "never again," but to commit ourselves to the understanding, empathy and compassion that is the foundation of peace and human dignity.

I think it's very important to remember that so much of the work that gets done between countries is not done at the level of presidents, but is done within various agencies, whether it's law enforcement or economic ministries. And when they establish relationships and systems of communications and shared projects and shared visions, those structures continue even after any particular president is gone. It builds trust and understanding between countries that are critically important.

A nation that can't control its energy sources can't control its future.

Obviously [my daughters] - and Michelle - have made a lot of sacrifices on behalf of my cockamamie ideas, the running for office and things.

Some technologies don't pan out; some companies fail. But I will not walk away from the promise of clean energy. ... I will not cede the wind or solar or battery industry to China or Germany because we refuse to make the same commitment here.

Be the best father you can be to your children. Because nothing is more important.

I think what is true is that there's been an underlying division in the United States. Some of it has to do with the fact that economic growth and recovery tends to be stronger in the cities and in urban areas. In some rural areas, particularly those that were reliant on manufacturing, there has been weaker growth, stagnation, people feeling as if their children won't do as well as they will.