A third federal judge has ruled the Partial-Birth Abortion Ban Act (search) unconstitutional, adding judicial weight that some experts say could keep the issue from reaching the U.S. Supreme Court.

U.S. District Judge Richard Kopf (search) of Lincoln ruled against the measure Wednesday, saying Congress ignored the most experienced doctors when it determined that the banned procedure would never be necessary to protect the health of the mother — a finding he called "unreasonable."

His ruling echoed decisions by federal judges in New York and San Francisco. The abortion ban was signed last year by President Bush (search) but was not enforced because the three judges agreed to hear constitutional challenges in simultaneous non-jury trials.

The ban, which President Clinton twice had vetoed, was seen by abortion rights activists as a fundamental departure from the Supreme Court's 1973 precedent in Roe v. Wade (search). But the Bush administration has argued that the so-called partial birth procedure is cruel and unnecessary and causes pain to the fetus.

If each judge is upheld by federal appeals courts, the high court might not take up the issue, said Pricilla Smith, a lawyer with the New York-based Center for Reproductive Rights (search).

"If all the appellate courts uphold those decisions, there is no reason for it to go to the Supreme Court," Smith said.

Not everyone agreed.

"It's very unusual for the court not to take a case where an act of Congress has been struck down," said Jay Sekulow, chief counsel for the American Center for Law and Justice, which supports the ban. "I would be very surprised if the court took a pass on this."

The Nebraska lawsuit was filed by the Center for Reproductive Rights on behalf of physicians including Dr. LeRoy Carhart, who also brought the challenge that led the high court in 2000 to overturn a similar ban passed by Nebraska lawmakers.

"The Supreme Court already said what the law is four years ago," Smith said. "The judges all across the country, from different political persuasions, applied the law and uniformly found it unconstitutional."

Louise Melling, director of the American Civil Liberties Union's Reproductive Freedom Project, agreed with Smith.

"What you have is a decision of a mere four years ago striking a similar ban," she said. "And now you have three courts striking a ban for the same reason."

Smith said, however, that if there is a change in the makeup of the high court through presidential appointments, it might still hear the issue even if the appeals courts uphold the decisions. "And that, of course, is what the proponents of the law have been hoping for all along," she said.

The Justice Department already has filed an appeal of the San Francisco ruling and said in a statement Wednesday that it "will continue to defend the law to protect innocent new life from partial-birth abortion."

In his ruling, Kopf said "according to responsible medical opinion, there are times when the banned procedure is medically necessary to preserve the health of a woman and a respectful reading of the congressional record proves that point.

"No reasonable and unbiased person could come to a different conclusion."

The federal law bars a procedure doctors called "intact dilation and extraction," or D&X, and opponents call partial-birth abortion. During the procedure, generally performed in the second trimester, a fetus is partially removed from the womb and its skull is punctured or crushed.

The law contains an exception when the life of the mother — but not her health — is at risk. Backers of the ban said a health exception would open a major loophole, allowing abortions even when the mental health of the mother is in question.

Kopf agreed with Carhart and his lawyers, who said the law is vague and could be interpreted as covering more common, less controversial procedures, including "dilatation and evacuation," or D&E, which is the most common method of second-trimester abortion.

A total of 1.3 million abortions are performed in the United States each year. Almost 90 percent occur in the first trimester.

An estimated 140,000 D&Es take place in the United States annually, compared with an estimated 2,200 to 5,000 D&X procedures.