"As you give voice to the voiceless I ask you to take comfort from this: The hearts of the American people are good," President George Bush told participants in the March for Life rally in Washington Tuesday. "Their minds are open to persuasion."

The abortion ruling remains as polarizing today as when it was decided by the Supreme Court in 1973.

To commemorate 35 years since Roe, the Planned Parenthood Action Fund, Planned Parenthood's political arm, said it would initiate a One Million Strong Campaign to get 1 million people to the polls in 2008.

"Reproductive freedom is still a political target for extremists," the organization said on its Web site, "and the battle isn't just being waged over abortion, but over access to contraception and medically accurate sex education."

Bush, a staunch abortion foe, said the anti-abortion movement must "work for a culture of life where a woman with an unplanned pregnancy" has support, an opportunity to complete her education and the "dignity of both the mother and child is honored and cherished."