Following yesterday’s context…
Bloomberg has done a lot for the city. I like the increased bike lanes and pedestrian zones in Times Square, Herald Square, and Madison Square that have appeared under his leadership, for example.
But personally I remember him most for what I saw as his lack of leadership during the 2004 Republican convention in New York City. People wanted to protest non-violently. The police refused permission to meet in Central Park, where larger groups had met before. The mayor’s voice was largely silent.
500,000 people intended to speak their minds non-violently. The police both prevented it and illegally arrested many protesters. Wikipedia, citing the New York Civil Liberties Union, says 90% of those arrests were overturned. 500,000 people is a substantial fraction of the United States voting public. Central Park is the city domain and he was silent, letting the police decide to suppress half a million voices. Whether you agree with the protesters or not, for a would-be leader to remain so silent on such a matter is ducking his responsibility.
We taxpayers had to pay for the police and judicial branch to resolve what appears as the police illegally quashing First Amendment rights. We’re probably still paying. That number of people speaking their minds would likely have affected the close Presidential election that led to dramatic differences in policy.
Why didn’t he speak then?
I suspect that despite his wealth and political power, with a Republican President and Governor, forces more powerful than he could manage figured out how to manage him.
I suspect now, like then, Bloomberg feels like Kennedy before the Bay of Pigs. Someone told him “Don’t worry, we’ll take care of everything. We know what to do.” He let them take care of it and things got out of control. Actions by bit players effectively made decisions for him he probably would not have.
My impression is that Mayor Bloomberg doesn’t fear speaking his mind in public. The day after the first Occupy Wall Street protest he said in a press conference.

People have a right to protest, and if they want to protest, we’ll be happy to make sure they have locations to do it… As long as they do it where other people’s rights are respected, this is the place where people can speak their minds, and that’s what makes New York New York.

Since then the actions of police — with their pepper spray, billy clubs, and mass arrests of non-violent protesters following their instructions — have spoken louder than any words of his.
As the twelfth richest American, his personal position can affect his credibility if he speaks inauthentically, or appears biased toward one side instead of toward upholding the law for all.
The irony is that Mayor Bloomberg is in the prime position to lead effectively — an intentional one, not a default difference through inaction. Thoughtful decisive action could turn the protests into an opportunity for the city, himself, and the country. Nobody else is in such a position and nobody else has the means to do it.
The core is that he doesn’t have to take a side on the issues. He only has to take a side on fostering lawful, non-violent, peaceful communication. People don’t want to protest, they want results. Police don’t want to jail people, they prefer people not protesting.
Give the people a voice with a reasonable chance to be heard and they’ll speak.
Tomorrow: recommendation: actions Mayor Bloomberg can take to benefit all