As a United States senator, I've got to do everything that I can to make sure that Trump does not become president.

I don't think any sensible person would disagree that the invasion of Iraq led to the massive level of instability that we're seeing right now. I think that was one of the worst foreign policy blunders in the modern history of the United States.

You can't become a billionaire stepping over children sleeping on the street.

I think, while it is true that the Hillary Clinton and I voted differently on the war in Iraq, what is important is that we learn the lesson of the war in Iraq. And that lesson is intrinsic to my foreign policy if elected president, is the United States cannot do it alone. We cannot be the policeman of the world. We are now spending more I believe than the next eight countries on defense. We have got to work in strong coalition with the major powers of the world and with those Muslim countries that are prepared to stand up and take on terrorism.

Hillary Clinton is a person who has enormous - I have enormous respect for, has a very distinguished career.

Subsidies for the oil, gas and coal industries are projected to cost taxpayers more than $135 billion in the coming decade. At a time when scientists tell us we need to reduce carbon pollution to prevent catastrophic climate change, it is absurd to provide massive subsidies that pad fossil-fuel companies' already enormous profits.

I worry very, very much about an isolated country. That's what makes me nervous. Russia lives in the world. China lives in the world. North Korea is a very, very strange country because it is so isolated, and I do feel that a nation with nuclear weapons, they have got to be dealt with. Dealt with effectively.