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.

[Donald Trump twitts] "Lightweight Marco Rubio was working hard last night." This is true. "The problem is he's chalker and once a chalker, always a choker," I guess that's what he meant to say. He spelled choker, c-h-o-k-e-r.

Muslim communities are the ones that going to see radicalization happening at a mosque or hear it in the community or even among their own family members. And the other part is that there is a narrative that ISIS and other jihadists pose that this is a war between Muslims and the rest of the world.

The terrorists that attacked us in San Bernardino was an American citizen, born and raised in this country. And I bet you we wish we would have had access to five years of his records so we could see who he was working with...

A president cannot make decision on what someone might know in the future.

We need 21st century programs. We have to change the dynamic because the world - we're not in the Industrial Revolution anymore, where you could leave high school, go work at the town factory for 50 years, and retire with a pension.

I'm always talking about the issue of Puerto Rico.I also spoke about it on the Senate floor, and I think it should be given the importance, the priority it deserves.