More than 30 years ago, U.S. Supreme Court Justice Harry Blackmun wrote a line that became the battle standard for affirmative action.

"In order to treat some persons equally," he said, "we must treat them differently."

It was an elegant, even poetic way of expressing an uncomfortable truth: that, sooner or later, promoting or admitting someone on the basis of race is going to involve shoving aside or passing over someone else for the same reason.

That said, it's a fact best left unflaunted.

With this in mind, proponents of affirmative action have performed contortions to obscure the reality of what they advocate. They've come up with euphemisms — positive action, diversity, outreach — to replace the very term, affirmative action, which was a euphemism itself when the Kennedy administration first employed it in 1961.

New Haven firefighter Gary Tinney in front of the New Haven firehouse where he works. Tinney is one of a group of African-American firefighters at the centre of a controversy over promotions and affirmative action, currently before the U.S. Supreme Court. (Bob Child/Associated Press)

Personnel managers, instructed to hit what are essentially hiring quotas, tend to submerge the cold math of what they must do.

They talk about using race as only one of many factors in their calculations and about emphasizing life experience, all the while assuring employees that advancing members of one group in no way means impeding members of another. The merit principle, they emphasize, remains supreme.

The logic argues with itself, but as long as de facto quotas, designed to reflect community makeup, are kept out of sight, workplace peace is maintained.

Enter the New Haven Twenty

That unspoken arrangement has been the modus vivendi of affirmative action in this country for nearly half a century. When personnel decisions are forced into the open, though, either by circumstance or by a court challenge, the public pays attention and the status quo becomes threatened.

Which is what happened this week as the New Haven Twenty, as members of the group call themselves, had their case heard before the U.S. Supreme Court.

All the 20 are firefighters in the city of New Haven, Conn. In 2003, they earned the highest scores among 77 applicants who sat for a promotion exam to fill 15 captain and lieutenant spots in the fire department.

The trouble was, the city had coded applicants by race and none of the 19 black firefighters who took the test placed in the top 20.

Some were close, but not close enough.

The city agonized for a few months and finally tore up the test results, concluding that the test, even though it had been painstakingly written to be "race-neutral," must have contained some sort of hidden bias the city could not identify. The open job positions were not filled.

A 'disparate impact'

New Haven reasoned it had no choice, given the Civil Rights Act of 1964, which prohibits government agencies from relying on any test that produces a "disparate impact" on any protected group.

In the U.S., of course, blacks are a protected group and from the perspective of organizations like the National Association of Professional Black Firefighters, the decision to ignore the test results was wise and just. But to Frank Ricci, one of the white firefighters, it was discrimination on the basis of colour — his colour — and, along with the other 19 high scorers, he sued.

Ricci and his co-plaintiffs make an argument that resonates powerfully with many Americans: that the U.S. Constitution guarantees them equal protection under the law.

The New Haven Twenty, say their lawyers, "ask nothing more than the basic right to be judged by who they are and what they have accomplished, not by the colour of their skin."

During the oral arguments this week, the high judges split along liberal-conservative lines, not unlike American society itself.

The conservative justices appeared to take some delight in piercing the careful, obfuscatory rhetoric of the pro-affirmative action lawyers, who argued the city does not discriminate against anyone on the basis of race.

Chief Justice John Roberts, who has written "the way to stop discrimination on the basis of race is to stop discriminating on the basis of race," bore in on a federal government lawyer who supported the city's decision to cancel the test results.

Could the government "assure me that the government's position would be the same," asked Roberts, if the test results had been reversed and no whites had scored in the top 20?

When the lawyer answered yes, the chief judge rolled his eyes.

Front of the line

Justice Antonin Scalia, another conservative, said the matter at hand was simple: "You had some applicants who were winners and their promotion was set aside."

But liberal judges on the court admonished the white firefighters for even bringing the case forward in the first place. Justice David Souter told their lawyer that these disgruntled applicants couldn't turn "any race-conscious decision into a discrimination decision."

The decider in this case will likely be Justice Anthony Kennedy, the courts's all-important swing vote, and he appeared unsympathetic to New Haven's logic.

The city "looked at the results and it classified the successful and unsuccessful applicants by race," he said. "And you want us to say this isn't race? I have trouble with that argument."

If the decision goes against the city, minority advocates fear it will sweep aside decades of entrenched rules designed to advance minorities at all levels of government.

Most likely, they will respond by trying to do away entirely with standardized tests, which, no matter how hard their designers try to eliminate so-called systemic bias, seem to end up with white applicants scoring better. (The city of Chicago just paid millions to a group of white employees to settle a similar case.)

Affirmative action supporters would rather rely on entirely subjective hiring and promotion criteria, such as interviews, which give managers far more discretion in reaching their targets.

The core question, though, which may not be answered here, is whether after nearly five decades of affirmative action, this country still needs hiring systems that move people to the front of the line based on race.

It may well. This is an ends-justify-the-means debate that has brilliant champions on both sides.

But even affirmative action's most passionate boosters acknowledge that the measures they advocate should not be permanent.

They were set in place to correct a deep social imbalance and the question is whether that imbalance has been sufficiently changed.

If that point has not been reached, and if such a socially divisive policy must continue, then doing away with seemingly objective, written tests and their potentially awkward results might be the wisest course.

The hand enforcing diversity, in other words, is best kept out of sight.