Seldom does any news send more waves of apprehension through the nation's capital than word of an approaching vacancy on the Supreme Court. Not so with the surprise report that Justice David Souter will retire at 69 before the start of its fall session.

The obvious reason is that Barack Obama is sitting in the White House now.

Abortion-rights advocates can breathe easy, confident that he won't choose anyone who will threaten reversal of their scared cow, Roe vs. Wade.

Over the last years of the previous Republican presidency, these folks spent many a sleepless night fearing that George W. Bush would add a third anti-abortion vote to the two he had already selected, Chief Justice John Roberts and Associate Justice Sam Alito.

Instead, they can be reasonably certain that if Obama does not select an unvarnished knee-jerk liberal to the vacancy, he will at least pick someone like Souter, who though seen originally as a conservative, over 18 years turned out to be a moderate who often voted with the court's minority liberal bloc.

The way Souter performed on the highest bench after the senior George Bush chose him in a way guaranteed the later nominations of a pair of reliable conservative votes in Roberts and Alito. The son who became president would at least learn that lesson from the father's "mistake," as the GOP's right wing might have put it.

Obama may not choose a card-carrying member of the abortion-rights community, but his own repeated views in support of a woman's right to choice on abortion give these folks a comfort level they never had while the Oval Office was in the hands of either of the Bushes.

Speculation has already focused on three women judges — two on federal appellate courts, Sonia Sotomayor of New York and Diane P. Wood of Chicago, and Obama's recently appointed solicitor general, Elena Kagan. One reason is that Justice Ruth Bader Ginsburg, 76, though recently recovered from cancer surgery but vowing to continue serving, could change her mind, leaving the Court without a woman on the Supreme Court.

Early reports have it that Vice President Joe Biden will assist Obama in compiling a list of prospective nominees. It's a role for which he is well suited after more than 21 years as chairman of the Senate Judiciary Committee, which provides the first and often critical review of all Supreme Court nominees.

Biden presided over the confirmation hearings of Souter, Ginsburg, Roberts and Alito as well as those of the late Chief Justice William Rehnquist and Associate Justices Anthony Kennedy and Clarence Thomas.

The confirmation hearings for Thomas, and before that for conservative nominee Robert Bork, provided some of the most controversial and avidly watched television hours in the history of the Court, and Biden himself emerged with mixed views of his stewardship.

Thomas, accused of sexual harassment by a former employee named Anita Hill who later became an Oklahoma University law professor, was denied a favorable recommendation from the Committee but then won confirmation by the full Senate. The 52-48 vote was the narrowest victory every recorded for the Supreme Court, with Biden voting against Thomas.

Bork was rejected after fierce and well-organized opposition from a broad coalition of civil rights and civil liberties groups, with Biden leading the effort. Though Biden was widely credited with conducting fair proceedings, the nominee's defeat created a new verb in political circles — of being "borked."

At a time when Obama has an inordinately full plate of serious domestic and foreign-policy problems facing him, he now has to make what he has said in the past would be one of his most important tasks as president. But with his own political position recently bolstered by the prospect of a filibuster-proof Senate, thanks to the party-switch defection of Sen. Arlen Specter of Pennsylvania, this one should be a slam-dunk.

Conservative Republicans may well say goodbye and good riddance to Souter, whose service on the Court has been a major disappointment to them over the last 18 years. But his replacement likely will add to the new political environment in which they are struggling to remain afloat.

Reach Jules Witcover at (Unknown address).

Reach Jules Witcover at juleswitcover@earthlink.net.