Washington, DC (LifeNews.com) -- The Supreme Court ruled 6-3 that the Bush administration cannot prohibit the use of federally controlled drugs from being used in assisted suicides in Oregon, the only state in the nation with a law allowing the grisly practice.

The majority, which included all of the Justices who back abortion, said federal law does not trump state law, even though the supremacy of federal law is normally upheld.

In 2001, former Attorney general John Ashfcroft said that Oregon doctors shouldn't be using drugs that are regulated by the Controlled Substances Act, which governs illegal narcotics, because the drugs do not constitute a "legitimate medical purpose."

Justice Anthony Kennedy, in the opinion for the majority, said the federal government has the authority to pursue drug dealers and pass health and safety rules under the law, but not to prosecute doctors using the drugs to kill patients.

The "authority claimed by the attorney general is both beyond his expertise and incongruous with the statutory purposes and design," Kennedy wrote.

Jay Sekulow, chief counsel for the ACLJ, said about the decision: "It is unfortunate that a majority of the court stripped the federal government of an important safeguard to ensure that federally controlled narcotics could not be used by licensed physicians to take the life of a patient who wants to commit suicide."

The case is the first major pro-life battle to involve new Chief Justice John Roberts and he sided with pro-life Justices Clarence Thomas and Antonin Scalia in dissent.

Kennedy's opinion was joined by pro-abortion Justices John Paul Stevens, David Souter, and Ruth Bader Ginsburg, and Stephen Breyer.

Retiring pro-abortion Justice Sandra Day O'Connor also sided with the majority and the Senate is expected to replace her with appeals court Judge Samuel Alito, who pro-life groups hope will be a pro-life vote.

Writing the dissent, Justice Antonin Scalia said federal officials have the power to regulate medicine.

"If the term 'legitimate medical purpose' has any meaning, it surely excludes the prescription of drugs to produce death,'' he wrote.

Thomas wrote his own dissent in which he said the reasoning used by the majority didn't make sense.

Responding to the decision, White House press secretary Scott McClellan said, "The president remains fully committed to building a culture of life, a culture of life that is built on valuing life at all stages.''

More than 200 people have used the Oregon law to kill themselves and pro-life groups have been worried about various ethical and procedural problems since the law was finalized in 1997.

The ruling is the third in a line of high court decisions on euthanasia and assisted suicide.

In 1990, the Supreme Court ruled that patients had a right to refuse lifesaving medical treatment and, in 1997, the court ruled unanimously that there is no constitutional right to assisted suicide but that states may ban or allow the practice.