The same way that laws against murder are enforced now. If sufficient hard evidence -- like, say, a body in a dumpster -- is reported to police, detectives will be dispatched to investigate whether or not a crime has occurred.
Would the police review medical charts to ensure doctors didn't assist in abortion?
Only if there were sufficient evidence to persuade a sitting judge to issue detectives a warrant for such investigation. You know, like in a regular murder investigation?
How would you keep a savvy girl from taking a massive dose of progesterone?
I don't imagine you could.
And savvy wife-abusers are able to keep Sallie-Mae from talking about "hubby gittin' a lil temper up"; but we still keep spousal abuse illegal, and dispatch detectives to investigate where there is hard evidence.
And what about the hapless, desperate girl who decides to use a coat hanger?
Mostly a myth, even pre-Roe.
The vast majority of abortions performed pre-Roe were performed by licensed physicians who liked to score some extra cash. Occasionally, however, one of them would slip up and leave a bag of dead babies in a dumpster, and they would be caught and prosecuted. Thus, even though most abortions went unreported and unprosecuted, society was still able to maintain at least a modicum of legal protection for unborn children, as well as maintain a strong social stigma favoring adoption and other non-violent alternatives.
I would suggest that it was more than a modicum of legal protection because the numbers of abortions committed post-Roe almost certainly skyrocketed. The phony statistics of millions of illegal "back alley" abortions, and huge numbers of maternal deaths put forth as rationalizations for legalizing it were later admitted to have been simply made up. You know, the same way as the numbers of the homeless in the Reagan Administration, or the numbers of Americans without health insurance, blah, blah, blah.
I think any prosecuter would tell you that all prosecution is selective. While much of it is a no-brainer, there are many instances where evidentiary problems might preclude it; not because the underlying acts are not crimes, but because there is a degree of uncertainty that the prosecution can be brought to a successful conclusion. However, that fact does not mean that we should throw the baby out with the bathwater, so to speak, and legalize the attacks on the baby.
The Supreme Court judges who unleashed the anarchy of Roe upon this Nation, and those after them who uphold its insanity, have turned the very purpose of law itself upside down. It wasn't said for nothing that the law is the great teacher. When its restraining influence is removed the lessons are very bitter, indeed.
Cordially,