If you're always in the company of people who agree with you, you're going to think of people who don't agree with you as venal or stupid. I constantly tell my students that if they're in the company of people who always say "amen" to what you say, find other company. And that is the source of illiberalism, when you are unable to listen to someone who thinks differently. That's when democracies are in trouble.

We don't want the smoking gun to be a mushroom cloud.

The United States government does not authorise or condone torture of detainees. Torture, and conspiracy to commit torture, are crimes under US law, wherever they may occur in the world.

Every life is worthy and every life is capable of greatness. We have an obligation to make sure that opportunity for greatness is there.

The American Founding Fathers gave us courts, independent jurists. They left room for civil society, which meant that citizens could directly associate in order to bring pressure on their governments. And they gave us a free press. They understood that you might have in the presidency someone who wanted to arrogate power into themselves. And they believed that was dangerous, having just experienced King George. And so they built a balanced system.

We needed to go back on the offense and offer clear leadership on Iraq.

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.