At The Volokh Conspiracy Todd Zywicki asks:
I've never met (or at least talked to) anyone who has gone from being pro-life to pro-choice. [...]If there are any readers out there who have made this migration (there must be), I'd be interested in hearing how that transition came about. In particular, what arguments did you find persuasive in changing your view on the morality of the issue?
In the comments, berkeleybeetle responds that zie did change:
because if we accept a fetus as an individual with rights, it has no right to attach itself to someone's womb and demand to be supported. I suppose, strictly speaking, this is pro-choice with the caveat that the fetus is told to come out with its hands up, first.
and shelbyc replies:
Even though, in most cases, the mother causes the fetus to become so attached for her own recreation, and the fetus has no choice in the matter? Funny logic.
One problem with this argument is that it relies on attributing a particular intent to all categories of a specific act, that is, under this argument every time a woman has sex (even when she is raped, even when she is using birth control) an implicit part of that sex act is that she has extended an irreversible invitation to a fetus. Another is that under this argument men have no agency: men's sexual acts do not impose a risk of pregnancy on women because it is the woman extending the invitation.