Terminally ill Oregonians are the only Americans who may legally ask their physicians to help end their lives.

The U.S. Department of Justice opposed Oregon's law both under former Attorney General John Ashcroft (search) and now Alberto Gonzales (search) and has been keen to see it overturned. On Wednesday, the U.S. Supreme Court will hear arguments in Gonzales v. Oregon (search), a debate on whether the U.S. attorney general or the voters of Oregon have the final say on physician-assisted suicide.

The Oregon Death With Dignity Act (search) was passed by ballot initiative in 1994, but because of legal conflicts it did not go into effect until 1997. The act made self-administration mandatory, barred lethal injection, forced participatory doctors to report to the state and applied only to terminally ill patients with less than six months to live.

More than 200 people have opted for legal assisted suicide (search), and some terminally ill Oregonians want it kept on the books.

"I know when all my treatment options have been exhausted, having the choice gives me comfort," Charlene Andrews, a Stage IV breast cancer patient from Oregon, said at a press briefing on Tuesday. "It's just knowing there's an option, knowing there's a choice. Oregonians like their choices."

The Justice Department is not telling Andrews she can't end her life. Rather, it is saying that the federal Controlled Substances Act allows the attorney general to decide whether a physician may administer a drug to facilitate suicide, and that federal authorities are authorized by Gonzales to prosecute physicians in Oregon who prescribe lethal doses to their patients.

Court watchers are eager to learn the votes of Supreme Court Justices Antonin Scalia, Clarence Thomas and Sandra Day O'Connor, who generally support states' authority but may defer to Gonzales if they find that the power granted him by Congress is legitimate. So the question at hand is not whether the Controlled Substances Act (CSA) trumps Oregon's law, but whether it grants the attorney general the power to trump Oregon's law.

Going by the text of the CSA alone, it might seem that Oregon is fighting a losing battle. The law says Gonzales has the power to deny or revoke the physician's registration if the physician is determined to have acted inconsistently "with the public interest." While drug-induced suicide may be a painless and peaceful way for a patient to end her suffering, arguing that her death serves a public good is trickier.

The Justice Department has also argued that assisted suicide falls outside the "accepted limits of medical practice." This is another difficult position for Oregon to counter, because based on the numbers alone, assisted suicide almost by definition falls outside "accepted limits."

"The question boils down to whether use of controlled substances in suicide is a legitimate medical use. The state says yes you're controlling pain, but the attorney general says no because ending life is not a core medical function," said Shannen Coffin, a partner at Washington's Steptoe & Johnson who was involved in the case as a deputy attorney general from 2002-2004.

Peg Sandeen, executive director of the Death With Dignity National Center, said states have traditionally determined laws governing the medical profession within their borders.

"It overstates the federal government's powers," Sandeen said of the Justice Department's interpretation of the CSA. "This would be just an unprecedented intrusion into the state's power to decide what medicine is."

While Oregon conjures up the government's victory in Gonzales v. Raich, which nullified state medical marijuana laws, it differs in ways that make the outcome unpredictable.

In the medical marijuana case, the justices determined that the federal ban on marijuana clearly outlawed any and all use of the substance in the country. Justice John Paul Stevens, who wrote the majority opinion, was careful to emphasize that the ruling was no indictment of medical marijuana users, just a reading of current federal law.

"The counter that will be made is that with marijuana, there is no appropriate medical use recognized by the Drug Enforcement Agency, but with the drugs that we're talking about in Oregon the feds just don't like the use being made," said William Colby, the plaintiff's attorney in Cruzan v. Director, Missouri Department of Health, the first right-to-die case argued before the Supreme Court.

While there is no federal law banning physician-assisted suicide, Ashcroft in 2001 released a directive stating "assisting suicide is not a legitimate medical purpose.” In Gonzales v. Oregon, the justices must decide if the "Ashcroft Directive," as it is known, is legitimate under the CSA.

Lauren Robel, dean of the Indiana University School of Law, said the justices could decide in favor of Oregon even if they agree with the federal government's interpretation of the CSA.

"If the court makes the determination that the statute actually authorizes the Ashcroft Directive, then the court will have to ask a follow-up question: Has Congress the power to intrude into an area typically left up to the states?" Robel said.

Because Congress has not spelled out restrictions on physician-assisted suicide, the majority justices in Raich may find themselves deferring to O'Connor's dissent in that case, which emphasized the role of the states as "laboratories" for policy.

"This could be a case that really garners a majority that goes across the line," Robel predicted.

Still, while the arguments in Oregon are mainly technical, it is hard to ignore the case's ethical implications. For that reason, said Vikram Amar of the University of California's Hastings College of Law, some justices' votes may be surprising.

"If we're going to read the attorney general's power narrowly here, it's got to be for some [special] reason, like the right to die context," Amar said. "This is a soft enough area of the law where the court has some discretion about what it wants to do."

Also on Wednesday, the Supreme Court will hear Schaffer v. Weast, which asks whether the burden of proof lies with plaintiffs or public schools in disputes involving the Individuals with Disabilities Education Act (search).