As the world's largest economy and second-largest carbon emitter, as a country with unsurpassed ability to drive innovation and scientific breakthroughs, as the country that people around the world continue to look to in times of crisis, we've got a vital role to play. We can't stand on the sidelines. We've got a unique responsibility.

No challenge poses a greater threat to future generations than climate change.

I miss Saturday morning, rolling out of bed, not shaving, getting into my car with my girls, driving to the supermarket, squeezing the fruit, getting my car washed, taking walks.

Sometimes I wonder how much of these debates have to do with the desire, the legitimate desire, for that history to be recognized. Because there is a psychic power to the recognition that is not satisfied with a universal program, it's not satisfied by the Affordable Care Act, or an expansion of Pell grants, or an expansion of the earned-income tax credit.

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

Undocumented workers can't report if they're not being paid overtime, or if their health and safety laws are being violated, of if they're not getting the minimum wage. And so a lot of times companies prefer to hire them in order to take advantage of them. We've got to crack down on those employers.

The problem is that, over time, big pieces of business that have to get done without leadership from Washington, don't get done.