While fueled by demagogic rhetoric and political opportunism, the current uproar over allegedly racist police practices in New York City and elsewhere has spotlighted one clearly abusive practice that moderates, conservatives, and, indeed, police chiefs should join liberals in assailing: racial profiling. That is the apparently widespread police habit of using skin color or ethnicity as a factor in deciding whom to stop and search for evidence of crime.

Just this week, New Jersey Gov. Christine Todd Whitman admitted that a 111-page internal review had confirmed a 1996 judicial ruling that some state police officers had engaged in racial profiling in deciding which cars to search during traffic stops on the turnpike.

Around the country, thousands of minority-group members have been humiliated by police stops and searches, often for conduct no more suspicious than "driving while black" or walking the streets of their communities. This, in turn, has helped to breed a deeply corrosive mistrust of law enforcement.

The full extent and the perniciousness of racial profiling are difficult to grasp for those of us who have not been targeted. The practice is virtually invisible to whites, except in the minority of cases in which police find illegal drugs or guns and make arrests. Almost all police organizations deny that they condone racial profiling. It is easily camouflaged by nonracial pretexts for searching cars and pedestrians; and it is sometimes confused with proper police work.

All this, plus the assumption that falling crime rates mean that the police must be doing something right, helps explain why moderate and conservative leaders have so far expressed relatively little concern about racial profiling. But the result has been to leave a void to be filled by race-card-carrying police-bashers such as Al Sharpton (sponsor of the Tawana Brawley hoax) and Jesse Jackson (who recently accused police in New York City of declaring "open season on blacks").

This issue is too important to be left to opportunists such as these. More law enforcement officials and politicians alike should recognize that whatever short-term benefits racial profiling may produce in catching a few criminals are far outweighed by the long-term costs. The biggest cost is the poisoning of police relations with minority-group communities, and thus with potential witnesses and jurors in the communities most in need of effective law enforcement.

While there have been few systematic studies of racial profiling, the scattered data collected so far are striking.

In New Jersey, the report released on April 20 showed that 77 percent of motorists searched on the turnpike were black or Hispanic, even though 60 percent of those stopped were white.

In Maryland, according to statistics compiled by state police as part of a 1995 court settlement, 70 percent of the drivers searched on a stretch of Interstate 95 from January 1995 through September 1996 were black — even though blacks made up only 17 percent of all drivers (and of all speeders) on that road, according to a related study by the American Civil Liberties Union.

Thus, an innocent black driver was four times as likely to be searched as an innocent white driver. And this was after the state police had (in the court settlement) issued a written policy barring race-based stops.

Studies of car stops in places ranging from Volusia County, Fla., to Eagle County, Colo., also reflect dramatic racial disparities. And in Louisiana, a state police training film a few years ago told officers to use traffic stops to do drug searches of "males of foreign nationalities, mainly Cubans, Colombians, Puerto Ricans, or other swarthy outlanders."

The most telling evidence of the extent and offensiveness of race-based stops and searches may be the personal accounts of the many black and Hispanic people who see such stops as emblematic of a discriminatory criminal justice system.

"You cannot talk to an African-American who has not either had this experience or had a relative go through it," says David A. Harris, a law professor at the University of Toledo, whose research on car stops and searches has included interviews with large numbers of middle-class blacks. "It’s a humiliating and angering experience," Harris reports. "One man said it’s like someone pulling your pants down around your ankles…. And any African-American who has teenage kids, especially male kids,… they’ve had ‘the talk’ with them, about what to do when — not if, when — they are stopped. This is in the nature of instructions for survival."

Is there any justification for racial profiling? Defenders of the practice point out that certain crimes are disproportionately committed by young black and Hispanic men — or by members of particular ethnic groups, such as Jamaicans or Colombians — and that police logically look for evidence where the criminals live, in the inner cities.

Such rationales reflect the tendency of practitioners and critics alike to confuse racial profiling with a different phenomenon: the policies of police in places like New York City to patrol (and stop, and search) most aggressively in high-crime neighborhoods. When done with respect and sensitivity, this can produce safer communities and better community relations. When it veers into wholesale intimidation, and indiscriminate frisking of young men on the street, it can become indistinguishable from racial profiling.

Even critics acknowledge that racial profiling is not entirely irrational in treating young black inner-city men as presumptively more worthy of attention than, say, grandmothers. Jesse Jackson himself implied this when he said in 1993: "There is nothing more painful to me at this stage in my life than to walk down the street and hear footsteps and start thinking about robbery — then look around and see somebody white and feel relieved."

A citizen such as Jackson might be justified in keeping a prudent distance from a group of black youths in certain settings. But a police officer would not be justified (absent some particularized basis for suspicion) in picking up a black youth, standing him against a wall, and frisking him.

While "it is rational to be more suspicious of a young black man than an elderly white woman," in the words of a trenchant new book by David Cole, No Equal Justice: Race and Class in the American Criminal Justice System, that "does not make it right. First, the correlation of race and crime remains a stereotype, and most blacks will not conform to the stereotype. . . . A police officer who relies on race in stopping and questioning individuals is therefore likely to stop many more innocent than guilty individuals. Second, our nation’s historical reliance on race for invidious discrimination renders suspect such consideration of race today, even if it might be ‘rational’ in some sense."

And outside of the inner cities, it’s unclear that such practices as race-based traffic stops on major highways — in which police are usually looking not for murderers, rapists, or robbers but for drugs — produce any significant law enforcement benefit at all.

Meanwhile, the costs mount, as innocent people who are searched come away feeling mistreated. This takes an incalculable toll on the willingness of many black and Hispanic citizens to cooperate with police, to provide leads, to testify as witnesses, and, when they serve as jurors, to convict guilty people.

What can be done about racial profiling? The practice is too deeply ingrained in police culture, and too easily camouflaged, to be eradicated by legislation or lawsuits. The best remedy may be for police chiefs to train their officers to shun such profiling, and to recruit more black and Hispanic officers.

In the short run, we need more studies to expose the extent of racial profiling. San Diego and San Jose, Calif., are both doing studies of their own police forces. Political pressure, lawsuits, and enlightened self-interest should spur other cities and states to do the same.

Meanwhile, Congress should give careful consideration to a proposal by Rep. John Conyers Jr., D-Mich., to require the Justice Department to collect and study racial and ethnic data about the drivers stopped and searched by state and local police.

Racial statistics can, of course, be manipulated to draw misleading inferences of discrimination, such as the wrongheaded notion that elite colleges discriminate against minorities by giving weight to Scholastic Aptitude Test scores in admissions. But unlike the case of SAT scores, racial profiling involves real discrimination. And on this issue, sunlight may be the best disinfectant.