No nation can meet the world's challenges alone.

Google "Donald Trump Iraq." And you will see the dozens of sources which verify that he was for the invasion of Iraq.

It plays right into the hands of ISIS. And that's why Americans need to know that Donald Trump's words are being used in recruitment videos that ISIS is putting out. I think that is a very serious problem.

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.

Incomes went up for everybody. Manufacturing jobs went up also in the 1990s, if we're actually going to look at the facts.

I think that I am the person who can do all aspects of the job. I think I'm the person best prepared to take the case to the Republicans. And I think that at the end of the day, it's not so much electability. It is who the American people can believe can keep them safe, can get the economy moving again, can get incomes rising, can build on the progressive accomplishments of President [Barack] Obama.

I have pretty thick skin. I've been in the arena a long time, and that means that I am not going to get down with [Donald Trump] and go insult for insult.