I’ve often said that global climate change is an issue where no one has the luxury of being “half-pregnant.” You either are or you aren’t. And so it is with climate change. You either understand and accept the science – or you don’t. Folks this isn’t a cafeteria where you can pick and choose and accept the science that tells us what is happening, but then reject the science that warns us what will happen.

What Donald Trump is doing is serving the polluters and serving a narrow group of ideological interests. That's not leadership. That's abdication of responsibility, and this step does not make America first. It makes America last.

I defended this country as a young man, and I will defend it as president.

You can't have responsibility and you can't have us living up to our ideals unless it's based on a fairly common acceptance of truth, of what is true - what is the truth here?

I'm against the partial-birth abortion, but you've got to have an exception for the life of the mother and the health of the mother under the strictest test of bodily injury to the mother.

What we have to do is go on the offensive. [The science on climate change] has been maligned and misinterpreted, and we need to fight back... [P]eople [need to] stop being moved by these talk show [hosts] and start looking for the facts themselves.

We cannot fight communism all over the world, and I think we should have learned that lesson by now.