We have to tackle the plague of gun violence.

The economy is rigged in favor of those at the top.

Wall Street can never be allowed to threaten main street again. No bank can be too big to fail, no executive too powerful to jail.

If you are too dangerous to get on a plane, you are too dangerous to buy a gun.

I think what Secretary Ash Carter is seeing, and I'm glad he is, is that we got to get NATO back working for the common defense. We've got to do more to support our partners in NATO, and we have to send a very clear message to Putin that this kind of belligerence, that this kind of testing of boundaries will have to be responded to. The best way to do that is to put more armor in, put more money from the Europeans in so they're actually contributing more to their own defense.

Donald [Trump] never tells you what he would do. Would he have started a war? Would he have bombed Iran? If he's going to criticize a deal that has been very successful in giving us access to Iranian facilities that we never had before, then he should tell us what his alternative would be.

I don't think any of us have the answers to everything. There's no human being on earth who fits that category. So why wouldn't you ask for help? Why wouldn't you run ideas by people that you respect? Too many young people cast around trying to figure out what the answer is themselves, because they're afraid to come back and say, "I'm not sure I understood you," or "Could you give me a little more information about what you need?" Just do that. It saves you time, it saves your boss's or mentor's time. And it's a great lesson to learn.