WASHINGTON - President Bush marked the 34th anniversary of the

Roe v. Wade

Supreme Court decision yesterday, telling thousands of abortion foes that he shared their goal of seeing "the day when every child is welcomed in life and protected into law."

Bush also signaled his unchanged opposition to a key goal of the Democrats who now control Congress: broadening embryonic stem-cell research.

"Our challenge is to make sure that science serves the cause of humanity instead of the other way around," the president said in a telephone call piped over loudspeakers to a Washington rally of opponents of abortion rights. "I have made clear to the Congress, we must pursue medical advances in the name of life, not at the expense of it."

Bush last year vetoed a bill bolstering embryonic stem-cell research, which advocates say shows promise for many medical cures. This month, the House passed such a bill again, though by a margin short of what would be required to overturn another veto from the president.

With abortion foes in a more defensive posture now that Democrats have gained control of Capitol Hill, Bush urged them to do more than look toward legislative victories.

"We've all got to remember that a true culture of life cannot be built by changing laws alone. We've all got to work hard to change hearts," he said. "The sanctity of life is written in the life of all men and women. And so I think, go forth with confidence that a cause rooted in human dignity and appealing to the best instincts of our citizens cannot fail."

Thousands of abortion foes from around the country gathered on the National Mall at midday for speeches. Several thousand later made their way to the Supreme Court, where they waved signs and chanted.

Police said there were no arrests during either protest.

The court is considering an abortion case now, dealing with the first nationwide restrictions on an abortion procedure since the landmark 1973 case.

The Bush administration is asking the court to uphold a law he signed in 2003 banning a procedure opponents call partial-birth abortion. It takes place most often in the middle-third of pregnancy.

The law calls the procedure gruesome, inhumane and never medically necessary. Abortion-rights advocates argue that such abortions sometimes are the safest alternatives for women.