I don't ken the emboldening. The positive duty for pro-abortionists is to make abortion accessible, free, legal, and a universal human right. This positive duty is obviously MORE (not "less") powerful than the negative duty — which is not to hinder abortion. Why? Just because pro-birthers don't hinder abortion, doesn't mean pro-birthers will donate money to fund abortions or report to the Royal College of Physicians physicians who don't abort women . Pro-birthers can be willfully blind.
Herring, Criminal Law: Text, Cases, and Materials (8 edn, 2018). p. 106
J. Dressler, ‘Some Brief Thoughts (Mostly Negative) about “Bad Samaritan” Laws’ (2000) 40 Santa Clara Law Review 971 at 981– 9 2.
There is one final reason to question the wisdom of BS [Bad Samaritan] statutes. Not only are positive duties morally less powerful than negative ones, but they also restrict human liberty to a greater degree. A penal law that prohibits a person from doing X (e.g. unjustifiably killing another person) permits that individual to do anything other than X (assuming no other negative duty). In contrast, a law that requires a person to do Y (e.g. help a bystander) bars that person from doing anything other than Y. The edict that ‘no student may laugh aloud at a fellow student’s silly answers to a professor’s questions’ only marginally restricts a student’s autonomy— she can silently laugh at her colleague, sleep through the answer, or walk out of the room to protest the student’s stupidity, just to name a few examples. However, a rule requiring a student to ‘provide reasonable assistance to a fellow student in jeopardy of offering a silly answer to a professor’s question,’ not only is less precise, but also prevents students from doing anything other than help.