So it turns out that we will not see a general election in which a New York candidate is at the top of each of three tickets, charmed though we were by the idea. Among the Republicans, Senator McCain’s victory in the Florida primary has ended Mayor Giuliani’s candidacy, and he is bowing out with grace and honor. Among the Democrats, Senator Clinton’s momentum was halted with her defeat in the South Carolina primary and by the endorsement of Senator Obama by Caroline Kennedy and her uncle, Senator Kennedy. One doesn’t have to gainsay the virtues of either Messrs. Obama or McCain to observe that if Mr. Bloomberg runs as an independent, he may yet be the best standard bearer of what we think of as the New York Idea.

The New York idea is about dynamism, open-ness, and the logic of capitalism and freedom. It comprehends that immigration makes America better. New York is, after all, the city that hosts the Statue of Liberty, a city that welcomed immigrants for years through Ellis Island and welcomes them today at John F. Kennedy International airport. New Yorkers understand that the virtues of immigration don’t depend on the paperwork but the value of human capital. We don’t mind saying that we wish both Messrs. Romney and Giuliani had pressed that point; it would have helped them.

The idea of New York encompasses, or even prizes, the success of capitalism. Our city is the capital of the financial industry, home to Wall Street, Goldman Sachs, the New York Stock Exchange, Merrill Lynch, Morgan Stanley, J.P. Morgan Chase, not to mention KKR and Blackstone and — well, the list goes on. The point to mark about it is that it is a list of engines of prosperity. It is not a list of the upper class, the rich versus the poor. New York stands for the idea that the poor can become rich and that if the rich don’t act wisely, they can become poor. New York is not immune to the nobler elements of the social idea, but it is an idea that human capital mixed with financial capital and freedom and the rule of law can create wealth.

It turns out that the New York idea includes the notion that partisan divides are not unconquerable. This is a city that while overwhelmingly Democratic in voter registration, has elected Republican mayors in the past four mayoral elections. It is a port city that understands trade. And it is a city of policy innovation, one that pioneered in reducing crime and welfare dependency, an example for American cities and for the country as a whole. New York understands the war in a personal way, but it picked itself up after the deadliest attack on our country and is now at an apogee. The idea of New York is one of optimism and hope and it bows to no one on the concept of change. If Mr. Bloomberg decides against entering the race, we’d like to think it will be because the other campaigns have picked up enough elements of the New York idea to explain their successes. But at the moment, we are at a juncture when it makes more sense than ever for Mr. Bloomberg to carry these ideas into the national campaign.