Standing on the mall Monday among the great and diverse crowd who came to celebrate the second inauguration of the President, I reacted strongly to two aspects of the day. The first was to the feeling produced by the crowd, to the moment itself. The second was something else, something perfectly clear: a new American “ demos ” has arrived. The demos of today, on display on the mall, was remarkable—a sea of people, supremely diverse in race, in age, in income levels, but united in the joy of the moment and in an ongoing sense of possibility for the future. It was a demos that stands in the cold and in long lines, not just at the inauguration but on Election Day through the night to exercise their rights as citizens. This is a new demos that demands that its diversity be more than simply cosmetic , but reflected in public policies that are more broad-based, inclusive, and committed to equality than those who have come before. And that breadth was fully reflected in the President's...