WASHINGTON – The Senate voted overwhelmingly Thursday to ban a procedure that critics call partial-birth abortion, and conservatives confidently predicted the bill would soon be signed into law after an eight-year struggle.

“This is a heinous act. It is immoral. It is wrong and it is simply something a civilized society should not tolerate,” Sen. Michael DeWine, R-Ohio, said after the bipartisan 64-33 vote to limit the range of procedures available to women under the 1973 landmark Supreme Court abortion rights ruling.

The Senate’s action cleared the way for expected House passage this spring. President Bush has said he will sign the measure, a revised version of bills that former President Clinton twice vetoed as unconstitutional.

“Partial-birth abortion is an abhorrent procedure that offends human dignity, and I commend the Senate for passing legislation to ban it,” the president said in a written statement. “Today’s action is an important step toward building a culture of life in America.”

Though outvoted, abortion rights supporters renewed a pledge to challenge the bill in court. “Anti-choice senators simply ignored Supreme Court precedent and voted to criminalize safe abortion procedures,” said Kate Michelman, the head of NARAL Pro-Choice America.

The bill prohibits doctors from committing an “overt act” designed to kill a partially delivered fetus. Partial birth is described as a case in which the entire fetal head is outside the body of the mother, or, in the event of a breech delivery, if “any part of the fetal trunk past the navel is outside the body of the mother.” Sponsors of the legislation say it is used roughly 2,200 times a year, principally during the 20th through 26th weeks of pregnancy.

The legislation includes an exemption for cases in which the life of the mother is jeopardized, but not for general health reasons.

Passage of the legislation was not in doubt in the Senate, and support crossed party lines. Voting in favor were 48 Republicans and 16 Democrats. Opposed were 29 Democrats, three Republicans and one independent.

Maine’s two GOP senators, Olympia J. Snowe and Susan M. Collins, voted against the bill.

Many supporters of abortion rights began abandoning defense of the procedure years ago – particularly after abortion foes began describing it in graphic detail. Public opinion polls show 70 percent support for a ban, although three states have rejected referenda to prohibit the procedure.

Sen. Barbara Boxer of California and other critics fought over three days of debate to derail the measure. In the end, they prevailed only on a nonbinding vote in support of the Supreme Court’s 1973 Roe v. Wade decision that gave women the right to end their pregnancies.

That vote Wednesday served to highlight the discomfort of abortion rights supporters.

A total of 17 members of the Senate voted first in support of a general right to abortion, then turned around less than 24 hours later and voted to ban the one specific procedure. Among them were Sen. Tom Daschle of South Dakota, the Democratic leader, Sen. Patrick Leahy of Vermont, the senior Democrat on the Judiciary Committee, and Sen. Lisa Murkowski, an Alaska Republican who took her seat this year and was casting her first votes in Congress on abortion.

At the same time, the presence of a majority in favor of the Roe v. Wade ruling left the Senate prognosis clouded for other items on the agenda of abortion opponents. They are expected to seek approval for restrictions on the distribution of foreign aid to groups that perform abortions, for example, and may seek to attach similar restrictions to legislation to create the international AIDS effort the president has asked Congress to approve.

Republicans also hope to pass long-stalled bankruptcy legislation, stripped of a provision that was designed to stop anti-abortion protesters from declaring bankruptcy to avoid paying court fines.

As for the measure passed Thursday, Sen. Rick Santorum, R-Pa., indicated that Republicans intend to drop the nonbinding provision from the legislation that is sent to Bush for his signature.

Rep. Steve Chabot, R-Ohio, said he hoped the House would vote next month. Bush’s promised signature would clear the way for a court battle.

The Supreme Court struck down a Nebraska law in 2000 that sought to ban the procedure, saying it created an undue burden on a woman’s right to end her pregnancy.

The court’s ruling cited two grounds, that the legislation failed to provide an exemption in cases in which the woman’s health was in danger, and that it defined the ban so broadly that more than one procedure could be affected.

Santorum said repeatedly in Senate debate that the bill had been drafted to address the court’s ruling, although Boxer and others disputed him on that.

The bill defines the banned procedure in different terms than an earlier version of the legislation. It states that the procedure is “never medically necessary.”

The legislation provides a jail term of up to two years for doctors who knowingly violate the ban.