When a conquering Roman general at the height of glory made his triumphal parade through the streets of Rome, a slave would be placed in his chariot to whisper in his ear, "You are but a man."

Lest he forget. We don't quite do it that way anymore, but the urge to keep the powerful from letting it get to their heads is perennial. Today, the great are even more exalted. A U.S. president doesn't just ride a fancy chariot; he rides a $1 billion flying palace. He doesn't just command the best legions in the world; he has a button that can bring on Armageddon. All the more reason to put a whisperer at his ear.We do. And whom do we Americans choose to keep a lid on the pretensions of the great man? A slave? A priest? A philosopher? A theologian? No. In typically American fashion, we saddle him with a lawyer - on whom we bestow the title "independent counsel," an unlimited budget, and the power to subpoena anything on two legs. We then turn him loose to remind the great one that he is very mortal indeed.

Conservatives, being partial to glory and mindful of the Constitution, were none too pleased when this innovation was introduced 20 years ago. The Founders had already made ample provision for checks and balances on the president's power, they argued, with Congress holding the ultimate power of impeachment. Beware this rogue fourth branch of government, they warned, with few checks, near unlimited authority and every incentive to carry out an unrelenting assault on the executive.

Democrats, until recently, remained unpersuaded. They were enjoying too much the spectacle of people like Ed Meese, Caspar Weinberger, Robert McFarlane and John Poindexter being harassed and/or brought low by a freelancing nemesis. Indeed, when Lawrence Walsh spent $47 million over seven years playing Ahab to the Reagan boys of Iran-Contra, he was held as something of a hero by the people now surrounding Bill Clinton.

Republicans screamed that Democrats were criminalizing policy differences. Democrats scoffed that they were merely enforcing the law.

In fact, the laws they were enforcing - the so-called Boland amendments restricting official U.S. funding for the Nicaraguan Contras - were among the most obscure and most oft-changed laws in postwar American history. Between 1982 and 1987 Congress changed its mind - and the law - at least five times regarding the permissibility of U.S. aid. There is hardly a living soul that can tell you what was allowed when.

Yet, for transgressing these baroque and often ambiguous mandates (by way of Iranian arms-deal money sent to the Contras), many high Reagan officials were driven out of office, some to ruin and one even to attempted suicide. At the time, Democrats evinced little sympathy for Walsh's victims. Now all of a sudden, with the Clinton administration under investigation for a list of charges staggering in its length and breadth - from Whitewater to campaign finances, from Indian casino deals to witness tampering - the Democrats are complaining that prosecution has turned to persecution, that policy differences are being criminalized.

What policy differences? Iran-Contra was about policy, a policy toward Nicaragua that Congress changed with the phases of the moon. Clinton's scandals are about less whimsical principles of law such as the prohibitions against looting banks and suborning perjury.

Moreover, in Iran-Contra, if the protagonists practiced deceit, they did so in pursuit of their vision of the national interest. They acted recklessly but selflessly. There was nothing in it for them.

Clinton's deceit, however, is practiced in pursuit and preservation of his own power. His corner-cutting and obfuscations are in the service of no country but himself. The Clinton scandals - from $100,000 cattle future jackpots to shady land deals to purloined FBI files - define the word corruption. Whitewater and White House interns are not the stuff of high national purpose.

And yet it is the investigation of these affairs that has led Democrats to suddenly discover the infirmities of the independent counsel statute. Well, better late than never. Partisan hypocrisy should not blind us to the truth: Independent counsels are an affront to our constitutional system.

Ken Starr has taken to issuing subpoenas to bookstores regarding the reading habits of noted Lewis and Clark College scholar Monica Lewinsky. Enough is enough. True, nothing can - nothing should - be done in mid-inquiry. Starr needs to finish. He is preparing his report to Congress. There may be indictments to return.

Fine. Let justice roll down like waters and righteousness like a mighty stream - one last time. But as soon as this set of inquisitors has finished its work, Republicans and Democrats should call it even - and call it off. No more special prosecutors. Don't mend it. End it.