The way Donald Trump talks about terrorism and his very insulting language towards Muslims is making him the recruiting sergeant for ISIS.

We do not have to choose between a healthy environment and a healthy economy.

I spent four and a half hours debating Donald Trump in three debates, which I think should put to rest any questions about my stamina.

I do have investments, investments in new jobs, investments in education, skill training, and the opportunities for people to get ahead and stay ahead. That's the kind of approach that will work.

The Russians need to understand. I think they've been treating it as almost a probing, how far would we go, how much would we do.

We got an international coalition [against Iran], and we imposed that. It was slow, patient diplomacy, nothing at all particularly headline-worthy. But then you got to the point where the negotiations - which I started and Secretary [John] Kerry completed - I think made the world safer.

We must stop thinking of the individual and start thinking about what is best for society.