The U.S. Supreme Court's 1973 Roe v. Wade ruling legalized abortion.
Some pro-choice supporters fear the ruling might be overturned if Republican presidential candidate George W. Bush wins the November election and appoints anti-abortion justices to replace outgoing justices.
It is possible that several justices will retire in the next four years, leaving the president to name replacements.
Well-known feminist Gloria Steinem discussed the importance of the controversial abortion pill and the next president's potential effect on women's rights during a conference call with student journalists Monday.
Democratic presidential candidate Al Gore sponsored the conference call.
Steinem, a Gore supporter, has pushed a pro-choice abortion stance since the 1970s.
She said RU-486's approval illustrates progress in the struggle for reproductive freedom using scientific methods.
Rep. Eleanor Holmes Norton, D-Washington, D.C., who also participated in the call, said she met with Steinem, civil rights activists and students to raise awareness that the Supreme Court's future depends on the Nov. 7 election.
"Most people think about bread-and-butter issues," Norton said.