Companies that pollute should be taxed so that a product's cost to society is reflected in the price of that product.

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.

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

Tax rates for the wealthy should revert to Clinton-era levels, both because it is necessary for long-term deficit reduction and because fairness dictates it. Moreover, there is no proof that higher marginal rates dissuade investment, all the rhetoric from the Right notwithstanding.

Imagine if investors in Wal-Mart really cared about bribery at that company's overseas operations or safety standards at its overseas manufacturing plants. If investors pulled their capital, corporate leaders would have to respond.

Our criminal justice system is fallible. We know it, even though we don't like to admit it. It is fallible despite the best efforts of most within it to do justice. And this fallibility is, at the end of the day, the most compelling, persuasive, and winning argument against a death penalty.

Imagine if the pension funds and endowments that own much of the equity in our financial services companies demanded that those companies revisit the way mortgages were marketed to those without adequate skills to understand the products they were being sold. Management would have to change the way things were done.