A few months ago, Jeanne Monahan was a think tank lecturer who nudged her antiabortion agenda at small meetings around Capitol Hill. Today, she is the head of the March for Life, the country’s largest antiabortion gathering, perhaps the key event abortion opponents watch each January.

The weight of that — and her speedy, unexpected rise — was very present Thursday as Monahan stood on an otherwise-empty stage on the Mall during a final walk-through for the march. A frigid wind whipped around as she looked out on the snowy grass where tens of thousands would gather the next day.

“Right now I’m saying a prayer. Lord, let this go off well,” smiled Monahan, who, at 40, is exactly the same age as Roe v. Wade, the landmark Supreme Court decision that established a woman’s right to an abortion. The anniversary this year is expected to boost the size of an event that commemorates the ruling and is already one of the Mall’s biggest annual marches.

Monahan embodies the movement’s transition. The photogenic, warm former federal government policy worker was picked in November to take over the March for Life after the death of Nellie Gray, the hard-line, media-unfriendly 88-year-old who ran the massive event almost single-handedly out of her home. Despite being an event primarily of youth, until last year the march had a bare-bones Web site and no accounts on Twitter or Facebook. Its main outreach to Congress (besides marching past the Capitol) had been passing out roses, which was banned after the anthrax scares of 2001.

Monahan’s charge is to modernize the march for a country that is becoming more conflicted about abortion even as it remains steadfastly committed to the Roe ruling and the value of personal choice. For the movement’s next generation of leaders, the question is whether those two things can coexist. Should the focus remain on Roe and changing laws to limit access to abortion, or has that left a legacy too judgmental for younger Americans? Should the emphasis shift to changing minds and hearts, particularly of women who are pregnant and don’t want to be?

Jeanne Monahan gives a short interview before speaking at a youth rally as part of the March of Life events at the Hyatt hotel. (Astrid Riecken/For The Washington Post)

There is debate among march participants as to exactly where the country stands on abortion. More and more Americans describe themselves as “pro-life,” yet majority support for Roe has remained steady for two decades. More state-level restrictions were passed in 2012 than in any previous year and the rate of abortions has been declining, yet one-third of American women have an abortion by age 45.

And the reelection of President Obama stung many in the antiabortion movement. Obama is strongly in favor of protecting access to abortion and contraception. He battled during his campaign with the hierarchy of the Catholic Church over the birth control mandate contained in the Affordable Care Act.

With this backdrop, Monahan is an apt face for the march. Unlike Gray, who came to loathe the media and took pride in not checking her voice mail even when it overflowed, Monahan is comfortable engaging not only the public but the divided nature of it. She speaks openly about different points of view on abortion even in her own Catholic family. This year, she launched the distribution of postcards for legislators — but the cards merely urged them to vote “pro-life,” without specifying particular measures.

Monahan knows opponents of abortion differ widely on policies and tactics. Since taking over this fall, she brainstormed the theme for this year, which echoes the movement’s hope to shift to “civil rights” language: “40 = 55m,” a reference to the anniversary of the Roe decision and the millions of abortions.

“The march brings everyone out, including those with strong opinions. You do see visual images of abortions, which is graphic — that’s not an approach I agree with, but people have a right,” she said in an interview this week. “Our march shows the joy and zeal of normal, pro-life Americans.

“Being pro-life is the new normal.”

Yet Monahan knows her movement is dealing with a complex picture — as do those who support abortion rights. Planned Parenthood recently announced it was moving away from the “pro-choice” label, hoping instead to highlight that each woman has a unique situation that can’t be prejudged.

At the same time, the antiabortion movement has sought to emphasize choice by funding and highlighting Crisis Pregnancy Centers, which seek to support women who don’t want to be pregnant so they don’t have an abortion.

“They have worked hard to co-opt the frame of ‘choice’ that worked in the past for pro-choicers. Their mantra now is, ‘We’re not out on the streets being violent, we’re just making sure women have choices and options,’ ” said Ziad Munson, a Lehigh University sociologist who studies movements, including the March for Life.

Munson said some of the thousands of centers across the country discourage workers from going to antiabortion marches so that potential clients don’t encounter, at a moment of crisis, faces they might interpret as strident.

Monahan is no stranger to the culture wars. Until taking over the march in November, she was the head of outreach on abortion and issues of “human dignity” at the Family Research Council, a conservative think tank and advocacy agency. She had resigned from the Department of Health and Human Services when Obama took office, unhappy with what she felt was a failure to emphasize marriage and sexual abstinence.

Others active in the movement say this campaign season was a particularly tough one, not only because of Obama’s reelection but because of the public outcry against antiabortion candidates who downplayed cases of rape victims.

“The movement has to look honestly at the last election, which can only be seen as a defeat,” said Michael Donohue, spokesman for the Catholic Diocese of Arlington. “Having said that, I think it’s still very significant that 40 years after Roe, this debate is so vital and even heated at times. I think many people when it was decided and even analysts would be surprised that this issue is as contested as it is. And that’s what the march shows.”