Barack Obama has said he doesn't believe in American leadership or America winning - he is wrong. America can win again and we will win again.

I think the debate was really some powerful moments of clarity. We saw that Donald Trump, substantively, has the same issues on issue after issue as Hillary Clinton. He agreed with Hillary Clinton on Libya, toppling the government in Libya. That led directly to Benghazi, led to handing that country over to radical Islamic terrorism.

I oppose amnesty, I oppose citizenship, I oppose legalization for illegal aliens. I always have and I always will.

Popularity isn't the end-all, be-all. What matters far more is that you stick to your principles, that you stand up and you live a life of integrity.

What data can tell you is if you have 10 messages, all of which you believe, it can tell you which messages are resonating and which aren't. And if you break it down even further, the truth of the matter is some messages resonate one place and other messages resonate another place.

I will sing their praises, I'll sing Donald's [Trump] praises and Marco's [Rubio] praises and everybody else's praises. But I'm going to keep the focus on substance and records. And there's a reason why they scream "Liar." Because when you point to their own records, their own voting records, their own words, they don't like their records because their records are inconsistent with what they're running on.

About 65 percent of Republicans believe that Donald Trump is not the best candidate to go head to head with Hillary Clinton.