NOM Chairman Maggie Gallagher writes at Patheos:

When I was, well, a few years younger than Tim Muldoon is today, the message of despair now directed at marriage was directed at the pro-life movement. All the powerful elites favored abortion. Media coverage of anyone who was pro-life was dreadful. All the wives of Republican power-brokers favored abortion rights. If you said you opposed abortion, people would shout, "You are calling my sister a murderer!" They informed me that by the time I turned 50, the pro-life movement would be dead because young people were so pro-choice.

I'm 50 now, and yet the pro-life sentiment is surging as today's young people are more pro-life than their elders.

How did that happen?

There are many ways to answer that question, and what I offer here is more of a missing piece—the role of politics in cultural change—than a comprehensive theory.