Well, the most important thing a president will be is commander-in-chief. And that requires having an understanding of the complex issues on foreign policy. Foreign policy presents us often with hard choices, not black or white choices.

I respect unions, I think they have an important role to pay and I listen to them, we meet with them, and they raise valid points on a lot of issues like worker safety and so forth, but I also respect the right of individual workers to decide whether they want to pay that fee and whether they want to join a union.

What's important to do is we must deal frontally with this threat of radical Islamists, especially from ISIS. This is the most sophisticated terror group that has ever threatened the world or the United States of America.

This opportunity – to make it to the middle class or beyond no matter where you start out in life – it isn't bestowed on us from Washington. It comes from a vibrant free economy where people can risk their own money to open a business.

I don't buy into the dystopian scenarios of self-aware robots enslaving mankind, but you don't have to be a sci-fi conspiracy theorist to acknowledge that plenty of good, well-paying jobs are being taken over by machines.

To tackle the big and relevant issues of the day with bold and innovative ideas is without question the most rewarding way to serve.

Barack Obama hasn't kept us safe. The problem is we had an attack in San Bernardino. And we were paying attention to the most important issue we have faced in a decade since 9/11, and then all the talk was about this proposal, which isn't going to happen.