NEW YORK (CNN) - New York's Attorney General Eliot Spitzer has conducted himself and his investigations of Wall Street in stellar fashion.

Spitzer deserves great credit for the $100 million settlement with Merrill Lynch in the analyst conflict-of-interest case. Spitzer deserves great credit for pressing the investigations of IPO allocations by Salomon Smith Barney and CS First Boston.... Attorney General Spitzer has Wall Street more than a little nervous about what he'll do next. And now the attorney general has me a little nervous as well, but for different reasons.

Wall Street is anxious that Spitzer will force institutions to change the way they do business: In effect, reinstitute the separation between brokerage and banking, as required by the now defunct Glass-Steagall Act, and to permanently separate investment banking and research. Sandy Weill, the head of Citigroup, which owns Salomon, is working hard to come up with a global settlement for all of Wall Street with both Spitzer and SEC Chairman Harvey Pitt. The pressure, particularly upon Spitzer, to agree to a global settlement is enormous.

Wall Street and the commercial bankers are warning that such permanent reforms could well do more damage than good... they're clucking loudly about damage to the capital markets of the country. Those would be the same capital markets that have cost investors $7 trillion dollars over the past two-and-a-half years. Of course the bankers and brokers are also the heart of the establishment in this country, with considerable influence on political fortunes, whether Democrat or Republican. That would include the political fate of the ambitious Spitzer. There's nothing pejorative about the word ambitious here. Thank goodness politicians of Spitzer's character and ability have aspirations.

And therein lies the reason for my nervousness. I hope that Mr. Spitzer will be able to withstand the forces arrayed against him. I hope the attorney general realizes he alone has a singular opportunity to create real reform, and perform an historically profound service to the nation. Real reform of wall street and the markets. To set new standards of conduct and accountability on Wall Street. And while doing so, put himself well beyond the moneyed establishment's implicitly-threatened constraint with his higher aspirations.