Perhaps I'm misremembering, but I don't recall him moving back to the center after the primaries in 2016. The shift makes sense... I don't think any hardline pro-lifers are going to flip to Biden anytime soon. (Not sure what to make of probability that some stay home due to the shift).

Whatever you think about abortion, there's no question it's popular. Hard stats are tough to come by (California doesn't report to the CDC, for example). If I understand Guttmacher, they contact every abortion provider in the US and ask for numbers, then extrapolate from there. In any event, it's in the neighborhood of a million abortions per year. (we bottomed out in 2017 at about 850k). Integrate that wrt time, subtract out the duplicates, and you've got a whole bunch of voters who have had abortions. I'm sure some of those voters regret their abortion, but that's a long way from believing they and/or the provider should be in prison.

My take: abortions are like vaccines: Don't want one? Don't get one.