We are very definitely in a new phase in the global terrorist threat where the so-called lone wolf could strike at any moment.

President Trump talks about extreme vetting, and we actually do have extreme vetting when it comes to refugee resettlement. Refugee resettlement is the most thorough, cumbersome, multilayered vetting system we have for the admission of anyone to the country.

In my view, and in the view of a lot of intelligence experts, the terrorist threat that we face now has morphed significantly from the days of 9/11 to homegrown violent extremism. We have to be concerned and focused on homegrown violent extremism, countering violent extremism that exists within our borders.

I'll never forget what a Catholic priest told me; he said, "If you try to padlock the door, you have to give people an alternative path - an alternative, safer path. You can't padlock, and you shouldn't padlock a burning building."

We are very definitely in a new phase in the global terrorist threat where the so-called lone wolf could strike at any moment.

If you build - if you spend billions of taxpayer dollars to build a wall over, let's say, a mountain, if you build a 10-foot wall over a 10,000-foot mountain, and someone is determined to climb the 10,000-foot mountain, they're not going to be deterred by the 10-foot wall. It's a matter of common sense.

There's a lot of sensitivity about federal involvement in elections around the country. I think that it would be appropriate to consider - whether there should be some basic federal minimum standards to the cybersecurity around the election infrastructure. We have federal standards for aviation security, for auto safety, for a lot of things, and elections are pretty important in the country.