If you happen to be in Manhattan on Monday, do not miss the Columbus Day parade gliding up Fifth Avenue. It will be a gaudy, joyful affair as always, but it will feature something especially timely. Its grand marshal is a brassy gent who took on Eliot Spitzer when the former New York governor as attorney general was at the height of his reckless powers, publicly slandering private citizens in the hopes of intimidating them into plea bargains while privately employing ladies of delight for what the FBI reported was "unsafe sex," perhaps undertaken at breakneck speed and without a seat belt. Let us pass on; "unsafe sex" does not invite prolonged contemplation in a serious column, and in this column, I am particularly serious. The Columbus Day grand marshal did something uniquely honorable and courageous.

He is Kenneth Langone, a self-made investment banker, venture capitalist and philanthropist. He is a co-founder of Home Depot Inc. Of even greater importance, he is a proud American who did not flinch when Spitzer went after him. He and an associate, Richard Grasso, spent some $70 million defending their good names after Spitzer trashed them. Then, several months after the former attorney general had trashed his own good name, they won. It took four years, but they won.

Those must have been harrowing years, for, though Langone is clearly a spirited and amusing adversary, he was under heavy fire. Back in 2004, Spitzer publicly called Langone, then head of the New York Stock Exchange's compensation committee, "unsavory," "deceptive" and "tainted." To his receptive stenographers in the media, Spitzer then went on to vow that he would put a "stake" through Langone's heart; so when Spitzer is accused of "unsafe sex," it might not be such a laughing matter. Actually, Langone laughed. In The Wall Street Journal, he characterized this threat as a "metaphorical threat" to his "cardiovascular system," as well as "brash talk." Denying he had broken the law as the grandstanding attorney general alleged, Langone went on to demonstrate that there was no case against him.

He was being accused of duping NYSE directors into approving the compensation package of the outgoing chairman, Grasso. Yet the directors denied that Langone had duped them by concealment or faked data -- those being Spitzer's charges. In fact, Langone demonstrated that it was Spitzer who was practicing concealment. The attorney general did not want what was called the Webb report, the compilation of evidence and charges against Langone, made public. When its contents were revealed, Langone was shown to be innocent.

In threatening executives such as Langone with scurrilous threats broadcast by a willing media, Spitzer's intent was always to intimidate them into out-of-court settlements. He tried this with others, for instance Hank Greenberg, the man who made AIG an insurance giant and who was driven out of the company by a cowardly board. The consequence of that prosecutorial excess cost the federal government a fortune in bailouts. The consensus among financial experts is that had Greenberg remained atop AIG, it never would have come to the grief it did.

Spitzer's barbarous use of his office "has never been adequately addressed in the media," remarks Lawrence Auriana, chairman of the Columbus Citizens Foundation, which is honoring Langone in Monday's parade. Auriana makes another worthwhile point. Had Langone not defended himself, "it would have been impossible to honor him Monday." His name would have been irretrievably defamed, says Auriana, "despite the hundreds of millions of dollars he has contributed to charities, the hundreds of thousands of jobs he has created and hundreds of millions of dollars in savings he has given the customers of Home Depot." A great exemplar of civic responsibility would be denied us.

Aside from being an ambitious attorney general who abused his power to attain higher office (remember that Spitzer rose to become the "reform governor" of New York), Spitzer was part of a wider movement to criminalize commerce. The movement began in the late 1940s, when sociologist Edwin Sutherland coined the term "white-collar crime" and set about to revise criminal law so that the prosecution of theretofore perfectly legal transactions could be possible. Sutherland wanted to eliminate the presumption of innocence, among other revisions. He was a leading theorist of the kind of class warfare that we see being practiced by certain members of the Obama administration today. With heroes like Kenneth Langone, the demagogues can be thwarted. If they are not, our economic woes will last a long time.