I actually believe that we need missile defense, because of Iran and North Korea and the potential for them to obtain or to launch nuclear weapons, but I also believe that, when we are only spending a few hundred million dollars on nuclear proliferation, then we're making a mistake.

We are now at a point where because we in fact have been successful at stopping a number of plots, a threat has evolved. We do see these lone-wolf actors. We do see these encouragements for troubled individuals to pick up a gun and act out of this ideology.

We run everything to ground. If you see something, say something. Report your concerns to law enforcement. They will be looked at, they will be reviewed.

Going back to the discussion we were having about immigration reform, some of the most challenging discussions I've had are with activists who essentially would argue that any immigrant from Central America, let's say, who gets here to this country should be allowed to stay because their country is dangerous, their country is poor, and the opportunities for that mom and that kid are much greater here, and why would you send them back?

And yes, my plan will continue to reduce the carbon pollution that is heating our planet - because climate change is not a hoax. More droughts and floods and wildfires are not a joke. They're a threat to our children's future. And in this election, you can do something about it.

A relentless focus on the outward markers of success can lead to complacency. It can make you lazy.

What we've seen at least since 1979 is Iran making constant, calculated decisions that allow it to preserve the regime, to expand their influence where they can, to be opportunistic, to create what they view as hedges against potential Israeli attack in the form of Hezbollah and other proxies in the region.