Washington ? The Supreme Court, weighing in on an issue with racial undertones, ruled Monday that federal judges have broad leeway to impose shorter prison terms for crack cocaine in a case that bolsters the argument for reducing the difference in sentences for crack and powder cocaine.

The court, by 7-2 votes in the crack case and one other involving drugs, upheld more lenient sentences imposed by judges who rejected federal sentencing guidelines as too harsh.

The decision was announced ahead of a vote scheduled for today by the U.S. Sentencing Commission, which sets the guidelines, that could cut prison time for as many as 19,500 federal inmates convicted of crack crimes.

Justice Ruth Bader Ginsburg, writing for the majority in the crack case, said a 15-year sentence given to Derrick Kimbrough was acceptable, even though federal sentencing guidelines called for Kimbrough to receive 19 to 22 years.

“In making that determination, the judge may consider the disparity between the guidelines’ treatment of crack and powder cocaine offenses,” Ginsburg said.

Kimbrough, a veteran of the first Gulf War, is black, as are more than 80 percent of federal defendants sentenced in crack cases.

By contrast, just over a quarter of those convicted of powder cocaine crimes last year were black.

The Sentencing Commission recently changed the guidelines to reduce the disparity in prison time for the two crimes.

New guidelines took effect Nov. 1 after Congress took no action to overturn the change. Today’s vote is whether to apply the guidelines retroactively.

Monday’s Supreme Court ruling grew out of a decision three years ago in which the justices ruled that judges need not strictly follow the sentencing guidelines.

Instead, appellate courts would review sentences for reasonableness, although the court has since struggled to define what it meant by that term.

The guidelines were established by the Sentencing Commission, at Congress’ direction, in the mid-1980s to help produce uniform punishments for similar crimes.

Justice Samuel Alito, who with Justice Clarence Thomas dissented in both cases, said that after Monday’s decisions, “Sentencing disparities will gradually increase.”