The current pro-life position *is* a product of modern politics. Continuity is more than just using the same arguments and logic. Otherwise you could argue there is significant continuity between the US government and the First Nations since they non-monarchies on the North American continent. Just because the current movement is recycling old arguments doesn't mean there's any connection between the two groups. And I should go look up the primary sources as I expect they sound more like "please save my baby from the
pater familias" than "life begins at conception." I also expect finding accurate translations to be difficult.
Gender roles vs "no gender roles" (as WS put it)? No, the concept of 'no gender roles' aka everyone does the same things is an innovation essentially borne of tech and industrial innovation. That was never part of the issue about abortion.
How to tell me you're unfamiliar with pro-choice thought without telling me you're unfamiliar with pro-choice thought.
Catholics are a bit player in the American pro-life movement. They might make noises about excommunication or try to embarrass pro-life Catholics but they aren't getting people elected.
The fact that participation in the public sphere seems to find itself at home with the pro-choice side is a powerful factor, and one the pro-life side does not seem to take seriously.
And why don't they take it seriously? Because keeping women at home is part of their objective. Given the groups involved in the pro-life movement, if abortion (and birth control) didn't make it easier for women to be independent, they wouldn't care at all. As evidenced by the historical lack of concern over the issue until Roe vs Wade and the development of medically safe abortions.
Also keep in mind that the pro-life movement's position (as shown by the laws being put in place) are no abortions, ever. Which makes even the strictest rabbi pro-choice.