I agree that his judgement is looking very poor. But in a GOP primary, regardless of his abortion stance, he's still a better choice than Trump. And in GOP terms, that's what would count for me.
Regarding the importance of abortion generally as an issue...
Didn't we just see the GOP win the House in spite of this? Maybe it did some damage, but those for whom it is the key issue are already not voting for the GOP.
My point isn't that the majority of women want to retain their control of these decisions. It's that they vote about other issues too and for a number of them, those other issues take priority.