Salon just published a piece saying that the gay rights movement has an advantage over the abortion rights movement, in that celebrities are willing to come out as gay, while few come out as having had an abortion.
This distinction can be parsed further though, in ways they do not: gay is an identity, having an abortion is an event - in a life full of other events.
Nonetheless, I said recently to my students that people will more readily admit to a drug addiction to an abortion. Most (especially the male students) seemed surprised by this. But it's obviously true: there is a tv show called Celebrity Rehab, not Celebrity Abortion Clinic.
I realise this is because abortion strikes at the twin axes on which women are most harshly judged. One: their sexual behaviour (if you need an abortion, you must be a slut having sex out of wedlock), and Two: their maternal skills (getting rid of a pregnancy is about as unmaternal as one can get). The women who tend to speak publicly about abortions are the repentant, putting it in the "terrible mistakes I made when I was young" category, not the "damn straight I did it and I'd do it again" school.
It's true that if women more willingly admitted to having ended pregnancies, this would have the power to overturn the debate on the issue: as politicians would realise how many women they know have made use of the right to choose.