With every case from years ago there should be lessons learned.

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.

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.

I think that ISIS is a problem and it's really a symptom of a much greater problem.

Politics, in my judgment, has become not just the means to a policy ends, but it's become the end itself. Politics has become the sport that we all watch, and we all pay attention to.

And we need a president who is a uniter, not a divider who can lower the temperature, not raise the temperature. And I wish President Trump would spend more time trying to go beyond his immediate base to reach people, and use the presidential microphone to try to bring people together, instead of the rhetoric that seems to divide us.

I think that the potential for homegrown terrorist attacks is something that we have to be very concerned about, because, in many respects, it's harder to detect when you have an independent actor who may be living in our midst, in our own communities.