WASHINGTON — Thousands of anti-abortion demonstrators marched through Washington to the steps of the U.S. Supreme Court on Friday to protest the landmark decision that legalized abortion.

The annual March for Life event took on added significance for many in the crowd, coming three days after the 40th anniversary of the decision in Roe v. Wade, the landmark Supreme Court case that legalized abortion in some circumstances. The demonstrators, carrying signs with messages such as “Defend Life” and “Defund Planned Parenthood,” shouted chants including “Hey, Hey, Ho, Ho, Roe v. Wade has got to go.” They packed the National Mall and surrounding streets for the March of Life.

“I just felt this 40th year marked a huge anniversary for the law,” said one demonstrator, Pam Tino, 52, of Easton, Mass, who also participated several years ago. “Forty is a very important year in the Bible as well, in terms of years in the desert. And I just felt like maybe this year that was going to be something miraculous that might happen. We might see something going forward with the cause.”

The large turnout reflected the relevance of the abortion debate four decades after the decision. Police no longer estimate crowd size, so it is difficult to judge how many people attended. The march permit was for 50,000 people, though organizers said the attendance was several times that number.

The March for Life is typically held Jan. 22, the anniversary of Roe v. Wade. This year, it was delayed until Friday to allow for cleanup after Monday’s presidential inauguration.

The right to abortion remains divisive, with no dramatic shift in viewpoint on either side; a new Pew Research Center poll finds 63 percent of U.S. adults opposed to overturning Roe, compared to 60 percent in 1992. Earlier this week, abortion opponents marked the anniversary with workshops, prayers and calls for more limits on abortion rights. And even as Obama this week reaffirmed his commitment to “reproductive freedom,” state legislatures continue to consider varied restrictions on a woman’s ability to receive an abortion.

Among the speakers at Friday’s rally was Rick Santorum, the former Pennsylvania senator and staunch abortion opponent who last year unsuccessfully sought the Republican presidential nomination.

He recalled the love and support the country showed for his young daughter Bella, who was born with a serious genetic condition and whose illness led him to take some time off from the campaign trail. He cited his daughter’s life — “she is joyful, she is sweet, she is all about love” — as a reason to discourage abortion even in instances when women are told it would be “better” for their unborn children to have one.

“We all know that death is never better — never better. Really what it’s about is saying is it would be easier for us, not better for her,” he said. “And I’m here to tell you ... Bella is better for us and we are better because of Bella.”

Material from The Washington Post is included in this report.