Our intelligence agencies will continue to gather information about the intentions of governments - as opposed to ordinary citizens - around the world, in the same way that the intelligence services of every other nation does. We will not apologize simply because our services may be more effective.

Immigration keeps this country young, it keeps it dynamic, we have entrepreneurs and strivers who come here and are willing to take risks, and that's part of the reason why America historically has been successful.

It ought to concern every person, because it is a debasement of our common humanity. It ought to concern every community, because it tears at our social fabric. It ought to concern every business, because it distorts markets. It ought to concern every nation, because it endangers public health and fuels violence and organized crime. I’m talking about the injustice, the outrage, of human trafficking, which must be called by its true name - modern slavery.

What we can be scientifically certain of is that our continued use of fossil fuels is pushing us to a point of no return

We forget now, but during his life, Dr. King wasn't always considered a unifying figure. Even after rising to prominence, even after winning the Nobel Peace Prize, Dr. King was vilified by many, denounced as a rabble rouser and an agitator, a communist and a radical. He was even attacked by his own people, by those who felt he was going too fast or those who felt he was going too slow; by those who felt he shouldn't meddle in issues like the Vietnam War or the rights of union workers.

One of the things I've learned about being president is that we'll work on issues for long periods of time, sometimes in obscurity.

Someday, our children, and our children’s children, will look at us in the eye and they'll ask us, did we do all that we could when we had the chance to deal with this problem and leave them a cleaner, safer, more stable world?