Few Americans have heard of Jonathan Blattmachr, a partner at Milbank, Tweed, Hadley & McCloy. But among the 16,000 or so lawyers in America who specialize in trusts and estates, which is to say in the passing of wealth from one generation to the next, he enjoys the status of a Hollywood star. In these circles, his first name alone prompts recognition.

Men (and a few women) of great wealth confide in Blattmachr. The Rockefellers are among those who seek his counsel. Because his specialty is maintaining wealth across time, he needs to know more than just the size and shape of his clients' fortunes. His work requires knowing whether a marriage is an enduring bond of love or a commercial relationship, or whether heirs can be trusted with fortunes or only allowed a stream of income. He knows of prodigal sons and promising granddaughters, of executives at family-owned businesses who will not learn for years that the brass ring was never going to be theirs. Sometimes men of great wealth whisper secrets they would never share with their wives. He knows how much a mistress costs or whether, if health fails, a spouse can be trusted with the power to pull the plug. His clients reveal these things to Blattmachr because he can help them maintain their wealth now and for their children. He can chart clandestine routes through the maze of the tax code, making a man who appears as a Midas to his bankers look like a pauper to the tax man.

Blattmachr helps the superrich keep their riches -- at the expense of everyone else. Sometimes the price is paid in higher taxes. More often it's paid in cuts in services or by borrowing from the next generation of taxpayers. He's not ashamed of this. His methods are perfectly legal. In fact, he sees himself not as someone who exploits the system for the benefit of the few but as the guy who keeps the system honest for everyone. For his job to have meaning -- and to score intellectually, which is his main source of satisfaction -- the tax system has to have integrity. It can't be corrupt or too easily foiled. Just as there is no honor in getting a criminal acquitted when the judge can be bought, there is no honor in finding a tax loophole when the code yields too easily to manipulation. His cat-and-mouse game is to work the loopholes in the system until the government finds them and draws them closed. And when he sees something in the code he considers egregious, he speaks up, as he did when he objected to the repeal of the estate tax. The repeal would ''shift the tax burden from the wealthy to everyone else,'' Blattmachr said one morning in one of his two offices, this one a sunny Park Avenue aerie from which he can look down on the great wealth machine that is Manhattan.

Given that shifting the tax burden one wealthy person at a time is Blattmachr's full-time occupation, a cynic might think that his opposition to the estate-tax repeal was just self-interest. But Blattmachr will have plenty of work, estate tax or not. There are always trusts to be designed and capital gains taxes to be cleverly avoided. The superrich will always be looking for ways to shelter their money. Blattmachr's objection to the repeal -- which, in the end, was restricted to just one year, 2010 -- is more complicated. It reflects his capacity to push and pull the rules to his clients' advantage, while still yearning for an ideal, principled law.