For the sake of our children and our future, we must do more to combat climate change.

What makes us exceptional - what makes us American - is our allegiance to an idea articulated in a declaration made more than two centuries ago: “We hold these truths to be self-evident, that all men are created equal; that they are endowed by their Creator with certain unalienable rights; that among these are life, liberty, and the pursuit of happiness.”

I don't know the facts of when Joe Soptic's wife got sick or when she died.

How we think about terrorism has to be defined and specific enough that it doesn't lead us to think that any horrible actions that take place around the world that are motivated in part by an extremist Islamic ideology is a direct threat to us or something that we have to wade into.

Well, I think that when you think about the challenges we face, these are challenges that require us to look forward and not backwards. When it comes to the economy I think we have to recognize that we are now in a global economy. And that the measure of our success is: how well are we training our workers? How well are we investing in the new energy economy?

In sectors like energy, I haven't been arguing for more spending per se; I've been arguing that it doesn't make sense for us to spend $4 billion subsidizing an oil industry that's mature and very profitable. We should be using that money to finance clean energy of the future.

American leadership is not simply a matter of going it alone and bearing all of the burden ourselves.