Federal law requires states to identify and improve disproportionate incarceration of members of minority groups. That law has been in place since 1992 and has prompted 40 states to develop programs to reduce minority involvement in the juvenile justice system.

Unfortunately, the requirement is under attack, and the Senate Judiciary Committee opposes an amendment to the juvenile crime bill that would preserve it. The resulting Republican juvenile justice bill would repeal the existing mandate, effectively closing our collective eyes to racial disparity in juvenile justice.

There is ample evidence of discrimination. Consider:

Minority youth are 33 percent of all youth aged 10 to 17, but 66 percent of those incarcerated.

Between 1982 and 1991, the height of the war on drugs, arrests of minority juveniles for drug offenses increased by 78 percent, while arrests of white juveniles decreased by 34 percent.

The Republican response to these figures is simple: Blacks and some other minorities commit more crime, and therefore they should be incarcerated more often. But that doesn't explain the disparities. If that were all that were going on, one would expect to see relatively consistent figures at each successive stage of the juvenile justice system. In fact, the disparities get progressively worse.

African American youth, for example, are 26 percent of arrests but 32 percent of those referred to juvenile court, 41 percent of those detained as delinquents and 52 percent of those tried as adults.

These disparities match similar figures in the criminal justice system's treatment of adults. The U.S. Public Health Service estimates that blacks are 14 percent of the nation's illegal drug users. Yet they are 35 percent of those arrested for drug possession, 55 percent of those convicted for drug possession and 74 percent of those sentenced to prison for drug possession.

If that evidence does not at least raise a question about discrimination, it is difficult to know what would. Yet the Republican bill discourages even the collection and assessment of evidence on racial disparities. Claiming, against all available evidence, that there is no problem, the Republicans' bill would keep us ignorant of the problem.

In fact, racial disparities in criminal justice generally are worse today than they were in 1950, when segregation was legal. Then, African Americans were 30 percent of the incarcerated population; today they represent more than half. The Justice Department reports that at current trends, one of every four black male babies born today will spend a year or more of his life in prison. And for every one black man who graduates college each year, 100 are arrested.

If those figures or anything like them applied to the white population, the politics of criminal and juvenile justice would be different. Instead of calls for mandatory minimums for "super-predators," trying juveniles as adults and "three-strikes-and-you're-out" laws, we'd be hearing about the need to keep kids in school, provide more community programs and improve job opportunities.

Current law directs states to identify the extent to which disproportionate minority confinement exists, assess the reasons why it exists and develop intervention strategies to address the causes. As a result, most states are making progress on this issue.

The Republican strategy of "see no evil, hear no evil," by contrast, is self-defeating. By discouraging the collection of information on the demographics of law enforcement, we exacerbate the already deep racial divide on this issue.

The House version of the Juvenile Crime bill, passed in the last Congress by 414-16, preserves the federal requirement to address disproportionate minority confinement. Having just missed in the Senate, we must now call on members of the House to insist that this protection of minority youth be kept when House and Senate conferees meet this month to work out differences between the two bills.

Paul Wellstone is a Democratic senator from Minnesota. David Cole is a law professor at Georgetown University.