I don't feel particularly courageous.

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.

We need to make it very clear - whether it's Russia, China, Iran or anybody else - the United States has much greater capacity. And we are not going to sit idly by and permit state actors to go after our information, our private-sector information or our public-sector information.

I want to have a tax on people who are making a million dollars. It's called the Buffett rule. Yes, Warren Buffett is the one who's gone out and said somebody like him should not be paying a lower tax rate than his secretary. I want to have a surcharge on incomes above $5 million.

Well, I think, by definition, all power has limits.

Every election is about the future, which by definition means it's more about the future of young people than it is about me.

I will not let anyone into America that I think poses a risk to us.