I wonder how much of this reflects sincere beliefs and how much is driven by political strategy.

By political strategy, I mean that they could think they’re up against an opponent pushing an extreme position (fetus = person) and must therefore push the opposite extreme (fetus has zero value) to balance it out. Perhaps they fear that starting from somewhere in the middle means the midpoint between their position and their opponents’ is too close to their opponents’ ideal, and would lead to more restrictive abortion laws.

That being said, I’m sure some of the people arguing that the fetus has no more value than some skin cells believe it. And, as you can see from my article, I, like you, disagree.