My measure?By what measure do you call one position "inherently extreme" and the other "inherently moderate". Sounds a lot like the "terrorist vs freedom fighter" debate we had in the press where I live about a social uprising, it all depends on your personal viewpoint.
In my view, the extreme angle of arguing against abortions is saying no abortions in any condition, under no circumstances whatsoever.
Allowing people to have a choice - moderate
Not allowing people to have a choice - extreme
It’s a pretty easy measuring stick to follow.