Abortion-rights leaders are aiming to change that. “We have a big, big challenge,” says Planned Parenthood president Gloria Feldt, who hopes the march will inspire a new wave of young abortion-rights activists. Recent polls show a steady erosion of support among the post-Roe generation. Last fall UCLA found that 55 percent of freshmen at more than 400 schools said abortion should be legal, down from 64 percent a decade earlier. In a February NEWSWEEK GENext Poll, only 3 percent of those 18 to 29 called abortion the most important issue America faces. Born long after the last back-alley abortion and raised under the pro-choice Clinton administration, the post-Roe set has learned to take legal abortion for granted. Some disagree with the abortion-rights movement entirely. “They just assumed we’d be on their side,” says Boston College student Kelly Kroll, 21, a former president of American Collegians for Life.

The trend has abortion-rights leaders sounding the alarm. With a hostile administration in the White House and control of the Supreme Court up for grabs in the next election, they see abortion facing its most serious threat in decades. “This generation of women doesn’t really believe they’re going to lose their right to choose,” says Kate Michelman, president of NARAL Pro-Choice America, one of seven groups sponsoring the march. After 18 years in her post, Michelman plans to step down at the end of the month.

Motivating the next generation may not be easy. At Wellesley College, Hillary Clinton’s famously feminist alma mater, just 55 students plan to board buses for Washington. Many others say they’re simply too busy. Emily Saunders, a 20-year-old English major from New York who says she’s pro-choice, doesn’t believe abortion is threatened. “Because it hasn’t been challenged I don’t feel like it’s something I have to defend,” she says. At Northwestern University, Sarah Brownlee, a 20-year-old junior, supports abortion rights but not old-style political activism. “I would never hold a sign that said my body, my choice or anything like that,” she says.

Organizers hope to convince the post-Roe crowd this isn’t their mothers’ abortion march. They’re spreading the word through blogs and online movies. Former Democratic presidential candidate Howard Dean has e-mailed to his list of nearly 700,000 supporters an Internet ad he taped with Michelman urging them to march. Punkvoter, a progressive coalition of punk musicians and record labels, is touting the march at concerts. And forget stodgy T shirts: how about a temporary tattoo with a pro-choice message in Chinese? A group of at least 3,000 students will lead the march and organizers hope that as many as a third of the estimated 1 million participants will be younger than 25.

Younger activists view abortion as part of a wider fight over privacy that stretches to birth control, emergency contraception and abstinence education. That broader outlook is reflected in the official march logo: “Choice, justice, access, health, abortion, global family planning.” It’s a slogan that could give young marchers more to believe in–or muddy the message so much, it gets lost in the crowd.