Ramesh investigated the "how many women have abortions" question back in 1999, it turns out:

The statistics are spotty - reporting requirements vary, and are often lax. But assume there have been about 35 million abortions since Roe v. Wade. A Statistical Abstract makes it possible to calculate how many American women have spent how many child-bearing years since Roe; it won't alter the numbers much to assume none of them have died. Accept, finally, the Alan Guttmacher Institute's estimate that 48 percent of abortions are repeats, and the calculation results in AGI's figure ... that 43 percent of women will have an abortion by age 45.

But this number doesn't account for repeat repeat abortions. The Centers for Disease Control has a 36-state estimate from 1995-1 have no idea how these states compare to the others-in which 10.7 percent of abortion patients had had two previous abortions and 6.7 percent had had 3 or more. Plugging those in yields a number closer to 33 percent of women having an abortion by age 45. The number would be a little lower if the abortion rate of the last ten years were used rather than the post-Roe average.

And of course at that point the abortion rate still had further to fall. Nonetheless, as Ramesh said then, "after any amount of fiddling ... it's still a dauntingly big number." It is indeed, and one can object to pro-choicers who massage the data to boost their side's case while still acknowledging their underlying point: Abortion is woven deeply into the fabric of American society, and in this sense, at least, the change that pro-lifers seek is a radical one.