The 15,000 walkers who gathered to defend the sanctity of life in the streets of San Francisco last month were certainly besieged. Protesting abortion in a city renowned for its rejection of traditional morality, in a state with one of the nation's highest abortion rates, is not a task for the faint of heart.

The pro-life men and women walking along the Embarcadero toward Marina Green were intent on staging a quiet, peaceful march marked by compassion for women affected by abortion. But the hundreds of counter-protestors who showed up that Saturday morning to oppose them were not nearly so diplomatic or discreet.

Furious that the Walk for Life would take place on their turf, San Francisco's pro-abortion activist groups had called for radical measures to stop the march. A group known as "Anarchist Action" had held public meetings to plan a counter-protest that would, according to its press release, "shut down the Walk for Life" and defend abortion rights "by any means necessary.” Abortion-rights supporters were urged to work together, but the release ominously noted that "autonomous direct actions to shut down the march are also encouraged."

On the day of the march, the pro-life walkers were flanked by hundreds of counter-protestors shouting obscenities, waving coat hangers, and mocking the Catholic Church. One pregnant woman bared her belly, on which she had scrawled in large black letters, “My baby is pro-choice.” Others wore red-stained nightshirts to symbolize the alleged dangers of outlawing abortion. Abortion-rights activists waved signs calling the pro-life walkers "Christian fascists" and "religious terrorists," urging them to "kill your kids" and "abort more Christians," and advocating "free abortions on demand." Some men dressed as cartoonish nuns with chalk-white face paint, mock religious habits, and fish-net stockings. Others wore buttons or carried signs depicting the cross with a red slash through it, or with a Swastika superimposed upon it.

There were far more offensive sights and sounds at the Walk for Life West Coast, but most cannot be described in a family newspaper. Thankfully for the pro-life marchers, the San Francisco police protected them from counter-protestors that the San Francisco Chronicle described as "loud and confrontational." Despite the harassment, the pro-lifers remained mostly silent as they marched behind a banner that said, "Abortion Hurts Women," breaking their silence only to pray and softly sing "Ave Maria" as pro-abortion activists repeatedly attempted to block their path.

The pro-life walkers finally arrived safely at Marina Green, where they beheld a breathtaking view of the Bay framed by the Golden Gate Bridge. In a city named for a peace-loving saint who had the courage to proclaim the Gospel without compromise, the brave men and women of the Walk for Life had succeeded in witnessing to a message too often ignored in San Francisco: Human life is not an accident; human persons are not disposable; and no human choice – not even the choice to abort a child – lies beyond the bounds of God's mercy.

That message terrified the abortion-rights activists in San Francisco, and they did everything they could to silence it. But the truth cannot be silenced forever. Like the quiet, steady progress of the pro-life walkers that day, America's pro-life movement is moving forward one step at a time. The momentum, like the truth itself, is on the side of life. And the truth will prevail.

--Colleen Carroll Campbell is a fellow at the Ethics and Public Policy Center in Washington, D.C.