In 1974, on the first anniversary of the Roe v Wade supreme court decision, abortion opponents gathered on the National Mall in Washington to “march for life”. They vowed to return each year until the ruling, which established the right to abortion, was no longer the law of the land.

On Friday, anti-abortion activists from across the country braved sub-zero temperatures and the coronavirus pandemic to assemble in Washington, more hopeful than ever that this would be their last march to a court where the fate of Roe will soon be decided.

“We are hoping and praying that this year, 2022, will bring a historic change for life,” Jeanne Mancini, president of the March for Life Education and Defense Fund, told a crowd tens of thousands strong and waving signs that read “I am the post-Roe generation” and “The future is anti-abortion”.

Praising followers for standing against what she called the “single-most critical rights abuse of our time”, Mancini said they sent a clear message to the supreme court: “Roe is not settled law.”

Chris Smith, a Republican congressman from New Jersey, described the mood as one of “fresh hope and heightened expectations”. The court’s conservative supermajority appears open to reversing Roe, thereby overturning nearly 50 years of precedent since the 1973 decision.

“There’s optimism in the air, there is a sense that a significant hurdle to protect the unborn is about to move,” he said.

The rally took place a day before the 49th anniversary of the Roe decision. The theme of the march, also in its 49th year, was “equality begins in the womb.” Speakers told rally-goers that their cause was bound up with the struggles for racial justice and gender equality and described abortion as “the ultimate form of discrimination”.

The march typically draws about 100,000 abortion opponents by the busload to Washington. But this year’s march took place amid a wave of Omicron infections in the nation’s capital that limited turnout.

Some activists said on social media they would not attend because of a new mandate in Washington requiring anyone over the age of 12 to show vaccination proof before entering restaurants, conference centers and other public places.

Still, the event attracted a large and enthusiastic crowd, priests, pastors and busloads of high school students, among them. Together after the rally they marched to the supreme court singing hymns and chanting “Hey hey, ho ho, Roe v Wade has got to go!”

The jubilant demonstration comes as the supreme court reviews a case involving a Mississippi law which bans abortion after 15 weeks of pregnancy, a direct challenge to Roe. At oral arguments, several members of the court’s conservative bloc appeared open to not only upholding the ban, but to overruling Roe entirely. A decision is expected by the end of June, months before the midterm elections.

“We’ve been building to this moment,” said Victoria Cobb, president of the Family Foundation of Virginia who spoke on a virtual panel organized by the March. Her group was active in helping confirm Amy Coney Barrett to the supreme court, part of a decades-long legal strategy by abortion opponents to remake the nation’s federal court system.

“We heard justices say that precedent shouldn’t be upheld if it was incorrectly decided in the first place,” Cobb said. “That’s a big deal.”

Several Republican lawmakers appeared on stage and virtually to voice their unwavering support for the anti-abortion cause, declaring that the movement was “winning this battle”.

Last year, states enacted more than 100 new abortion restrictions, a record, according to the Guttmacher Institute, a research organization that supports reproductive rights and tracks state-level legislation. The group has called 2021 “the worst year for abortion rights in almost half a century”, and estimates that 26 US states are “certain or likely” to immediately ban abortion if Roe is overturned.

And conservative states are already laying the groundwork for new restrictions as fights over issues like telemedicine and abortion pills gain momentum.

Though the anti-abortion movement has made significant legal and policy gains in recent decades, public opinion polls have consistently found that a majority of Americans believe abortion should be legal in all or some circumstances.

“If Roe falls, the battle lines will change,” Mancini said. “But make no mistake, the fight for life will need to continue in the states.”

Kelly and Greg King, a married couple from Los Angeles, who were attending the event for a third time, said the supreme court decision would likely push their state to expand abortion access. They worry about plans to make California a “sanctuary” for out-of-state patients seeking reproductive care in a post-Roe legal landscape.

Clear-eyed about the state’s progressive politics, Kelly King said she would focus her efforts on “changing hearts” rather than changing policy.

“Abortion has become … ” Kelly King said, searching for the word. “Normalized,” her husband chimed in. “Yes, normalized,” she said. “That’s the problem.”

Hours before marchers arrived on the National Mall, the supreme court declined to accelerate a legal challenge to a Texas law that has effectively banned abortions in the second-largest state.

Yet among the speakers, there were few references to that victory or to the Texas law, which is deeply unpopular, including among Republicans.

Pro-choice supporters also marked the anniversary, using the occasion to “sound the alarm” on the threat posed to reproductive rights.

Mini Timmaraju, the president of NARAL Pro-Choice America, warned that a “small but vocal minority” was “determined to undermine the will of the majority of people in this country who support reproductive freedom”.

“They falsely claim to be supporters of ‘equality’ all while working ardently to block abortion access and end the legal right to abortion,” she said in a statement. “Make no mistake – this movement’s end goals would only criminalize and endanger people based on pregnancy outcomes, furthering inequality.”

At the White House, press secretary Jen Psaki noted the anniversary of Roe v Wade during her press briefing, saying that “reproductive healthcare has been under extreme and relentless assault ever since, especially in recent months”.

She said the Biden administration was committed to working with Congress to pass federal legislation essentially enshrining into law a woman’s right to an abortion. The Democratic-controlled House passed the bill last year, but it remains stalled in the Senate, where it faces a Republican filibuster.

“We’re deeply committed to making sure everyone has access to care and we will defend it with every tool we have,” Psaki said.

At the rally, the presence of Make America Great Again hats was a reminder of the mutually beneficial relationship forged between Christian conservatives and Donald Trump, who became the first sitting president to attend the event in 2020.

As they gathered, Trump voiced his allegiance: “As you gather together today for the March for Life, I am with you in spirit!”

While many of the speakers anticipated the end of Roe, several demonstrators said they would continue to attend future marches until its mission “to make abortion unthinkable” was achieved.

“I just pray every year that this is the last year we’re here,” said Janice LePage, who works for the youth ministry in the Archdiocese of St Louis. “I’m praying that the following year will be a march of celebration.”