Whether Jackson has the discretion to ignore the guidelines is the issue before the Supreme Court on Tuesday.

A companion case from Iowa also involves a judge's discretion to impose a more lenient sentence in a drug case, although Brian Gall pleaded guilty to conspiracy to distribute ecstasy. In Gall's case, the judge decided probation was sufficient punishment even though the guidelines called for prison time.

Federal appeals courts threw out both sentences, but the justices accepted the defendants' appeals.

The Bush administration is supporting the appeals court rulings, while civil rights and advocacy groups are backing the defendants.

Congressional opponents of the laws establishing more severe sentencing for crack cocaine than powdered cocaine are racially discriminatory because they hit more directly at the black community, where this form of drug abuse is more commonplace.

Advocates for reducing the disparity point to crime statistics that show crack is more of an urban and minority drug while cocaine powder is used more often by the affluent. They say harsher penalties for crack cocaine unfairly punish blacks.

More than four-fifths of crack cocaine offenders in federal courts last year were black, according to the U.S. Sentencing Commission. By contrast, just over a quarter of those convicted of powder cocaine crimes last year were black, the commission said.

Kimbrough actually had much more powder than crack, but it was the latter that determined the length of his prison term.

The 4th U.S. Circuit Court of Appeals in Richmond said judges are not free to impose sentences shorter than the guidelines "based on a disagreement with the sentencing disparity for crack and powder cocaine offenses."

The crack-powder disparity grew out of a 1986 law that was passed in response to violent crimes committed to get money to feed crack habits.

The law includes what critics have called the 100-to-1 disparity: Trafficking in 5 grams of crack cocaine carries a mandatory five-year prison sentence, but it takes 500 grams of cocaine powder to warrant the same sentence.

The U.S. Sentencing Commission, an independent agency within the U.S. judiciary, voted in May to reduce the recommended sentencing ranges for people convicted of crack possession, a step toward lessening the disparity. The recommendation will become effective Nov. 1 unless Congress acts.

At the same time, the commission urged Congress to repeal the mandatory prison term for simple possession and increase the amount of crack required to trigger obligatory five-year or more prison terms as a way to focus on major drug traffickers.

The Supreme Court gave a boost to judges' discretion when it ruled in 2005 that the sentencing guidelines are advisory, not mandatory. The guidelines were adopted in the 1980s to ensure comparable sentences for similar crimes from courtroom to courtroom.

In the other issue appealed to the nation's highest court, the industry said the generalized jury findings rested on evidence, arguments and theories of liability that were preempted by a federal law, the Federal Cigarette Labeling and Advertising Act.

A Miami jury ruled in 2000 that the tobacco companies deceived smokers about the dangers of cigarettes and ordered the companies to pay $145 billion to ailing Florida smokers, estimated to number about 700,000.

The case, filed by Miami Beach pediatrician Howard Engle in 1994, was the first smokers' lawsuit to be certified as a class action.

But a Florida appeals court overturned the punitive damages award and decertified the class action, a ruling upheld by the Florida Supreme Court.

Defendants in the case included Altria Group Inc's Philip Morris USA unit; the R.J. Reynolds Tobacco Co and Brown & Williamson units of Reynolds American Inc; the Lorillard Tobacco Co unit of Loews Corp., which trades as Carolina Group; and Vector Group Ltd's  Liggett.

In the Supreme Court appeal, the companies said the constitutional right of due process "prohibits a state court from giving preclusive effect to a jury verdict when it is impossible to discern which of numerous alternative grounds formed the basis for the jury's finding of wrongful conduct."

They also argued that a plaintiff may not avoid federal preemption under a 1992 Supreme Court ruling by merely invoking characterizations such as "fraud" and "negligence." 

Proponents of the laws that have been passed since the contested 2000 presidential election say the measures combat fraud. But opponents said poor people and minorities who often don't have driver's licenses, passports or other government-issued identification would be excluded from the polls.

Seven states require a photo identification to vote and 17 states require identification without photos. The battle has broken down over partisan lines with Republicans favoring laws they said would combat voter fraud while Democrats have pushed proposals they said would encourage more voter participation.

The voter identification case is from Indiana, where Secretary of State Todd Rokita, a Republican, said "voter fraud exists and Hoosiers shouldn't have to become further victims of it."

But state Democratic Party chairman Dan Parker, whose party urged the court to take the case, said Republicans have "relied on fear and flimsy legal logic to push through a policy that deters voting instead of promoting it."

A spokesman for the Republican National Committee responded cautiously to the announcement. "We are pleased that the Supreme Court is bringing attention to this important issue," Danny Diaz said.

"This is another step to ensure that every citizen who is eligible to vote will have that right."

Donna Brazile, a Democratic strategist who heads the DNC Voting Rights Institute, likened voter requirements to a "modern-day poll tax" designed to disenfranchise black and poor voters.

"Some of us in the voting rights community are very nervous because we fear the court will make matters worse," she said.

"This is a tremendous victory for the civil liberties of young adults," said Kary Moss, executive director of the ACLU of Michigan.

Under the 1998 law, pedestrians under 21 who refuse to take a breath test face a $100 fine. To require a breath analysis, an officer must have reasonable cause to believe that a minor has been drinking.

Backers of the law have said police need breath testers and other tools to enforce the legal drinking age.

In 2006, the city of Mount Pleasant and Isabella County agreed to pay $5,000 to two of the plaintiffs, Cullin Stewart and Samuel Maness, and stop warrantless pedestrian breath tests until Lawson issued a final ruling.

Both Stewart and Maness attended a 2003 post-prom party in Isabella County where, according to the lawsuit, an interagency police task force called the "Party Patrol" broke up the party, placed the students in a circle and asked if they had been drinking.

They had to blow into a portable breath tester, according to the suit. Stewart was not charged, but Maness was issued a citation accusing him of being a minor in possession of alcohol.

Michigan State Police, Central Michigan University and Saginaw County's Thomas Township Police Department also are defendants in the case.

A telephone message seeking comment was left at the office of state police spokeswoman Shanon Akans.

The Supreme Court will now examine whether a fatal three-drug cocktail most of the states use to execute inmates may violate the ban on cruel and unusual punishment.

Among the four key questions the justices will consider is whether states can execute an inmate if there is a "substantial risk" of pain and suffering through lethal injection.

By taking the Kentucky case, the justices are expected to provide a road map for judges across the country, including in California, where a San Jose federal judge has been reviewing the issue for more than a year.

"They decided to take the bull by the horns," said Ronald Matthias, a senior assistant attorney general in charge of California's death penalty appeals. "It is a very significant development, and we expect a very far-reaching and important decision which we'll obviously be bound by."

The Supreme Court review is likely to further delay California's effort to resume executing death row inmates.

Matthias would not speculate whether the court's intervention would halt the ongoing challenge in California by death row inmate Michael Morales, whose case has prompted Gov. Arnold Schwarzenegger to overhaul the state's lethal injection procedures.

U.S. District Judge Jeremy Fogel is scheduled to hold additional hearings on the Morales case in December and to tour a newly constructed death chamber in November. But some legal experts now expect the case may wait until the Supreme Court makes its ruling.

California has put executions on hold since early 2006 while Fogel has been reviewing Morales' lawsuit, which maintains the state's lethal injection method poses an undue risk of an inhumane execution for the more than 650 inmates on the state's death row.

John Grele, one of Morales' lawyers, said he would need to review the Kentucky case more closely to determine its effect on the California litigation.

But legal experts agreed the decision to hear the Kentucky case would have broad implications for states across the country, particularly given the scattershot results that have come from different courts asked to review the arguments of death row inmates.

In some states, executions have been put on hold, whereas other states have kept executing people despite nearly identical challenges pending in their courts.

The Supreme Court's decision to take the Kentucky case is "huge news" that should lead to a "de facto moratorium" on executions nationwide, Douglas Berman, an Ohio State University law professor and leading expert on the issue, said on his law blog. Berman does not expect a ruling until the end of the court's next term, in June.

Elisabeth Semel, head of the death penalty clinic at UC Berkeley's Boalt Hall School of Law, said the case is crucial to settling questions surrounding lethal injection but cautioned that the justices do not necessarily have to settle them all.

"The court is taking a bite of the apple," she said. "But how big a bite is not known."

"It puts Judge Fogel and other judges in the middle of this process in a position where they have to step back," she added.

A Supreme Court review of lethal injection has been brewing for years. Most states with a death penalty have turned to the method after similar legal challenges of alternatives, such as the gas chamber and the electric chair.

A federal appeals court declared California's gas chamber unconstitutional in the mid-1990s, prompting the switch to lethal injection.

In recent years, the Supreme Court has been repeatedly asked to review challenges to various states' lethal injection procedures but has steered clear of the central constitutional issue. The justices did make it easier for condemned inmates to file challenges, prompting a number of cases to unfold in states such as Missouri, Tennessee and Kentucky.

A federal judge in Tennessee recently put executions on hold there after concluding that the state's lethal injection method was too flawed. Fogel, in the California case, called this state's execution procedures "broken" but fixable.

In the Kentucky case, the state courts rejected challenges from death row inmates Ralph Baze and Clyde Bowling Jr. after a trial was held in 2005 to review Kentucky's execution method. It was the Baze and Bowling case the Supreme Court agreed Tuesday to hear.

Kentucky uses the same three drugs to put an inmate to death as California -- sodium thiopental to sedate the inmate, pancurium bromide to paralyze the muscles in breathing and potassium chloride, which stops the heart.

Lawyers for death row inmates say pancurium bromide conceals an inmate's suffering and masks the potential of the third drug, causing a searingly painful death.

One of the four issues the Supreme Court may address is whether it is unconstitutional to use those three drugs if other chemicals are available that pose "less risk of pain and suffering."

But legal experts say the court's ultimate ruling may focus more on how a state administers those drugs, rather than what drugs are used.

The Supreme Court, experts say, can instead clarify the standard for what amounts to a cruel and unusual execution and the obligations of states to administer the fatal drugs with proper safeguards.

All but one of the states with the death penalty and the federal government use lethal injection for executions. The only exception is Nebraska, which requires electrocution.

The standard method involves administering three separate chemicals: sodium pentothal, an anesthetic, which makes the inmate unconscious; pancuronium bromide, which paralyzes all muscles except the heart, and then potassium chloride, which stops the heart, causing death.

Attorneys for the two Kentucky men said at least half of the death row inmates facing imminent execution in the last two years have filed suit challenging the chemicals used in lethal injections. While various lower court federal judges have ruled on the issue, the Supreme Court has yet to decide it.