Yes, people pull the trigger - but guns are the instrument of death. Gun control is necessary, and delay means more death and horror.

Global warming threatens our health, our economy, our natural resources, and our children's future. It is clear we must act.

As someone with a deep faith in competition and the market, I also know that markets only work with tough enforcement of the rules that guarantee competition and fair play - and that the pressure to break those rules only gets stronger as the amount of money involved gets larger.

I think President Obama could have handled politics and policies differently. But he has been decisive, strong, and consistent - important qualities in a president. Mitt Romney is indeed an Etch A Sketch, the antithesis of leadership.

Power must be used, but it must be tempered by soul-searching and the recognition of our human capacity for error. That is the maxim that should inform our approach to every challenge, from reforming state government to engaging in foreign affairs.

I believe in an evolving Constitution. A flexible Constitution leaves room for us to consider not merely how the world once was, but how it ought to be.

When you're in office, there are tangible moments when you can see tangible successes.