I like a good conspiracy theory as much as anyone, but is it really so hard to believe that people could object to abortion on religious grounds? I agree that anyone rich would have little problem flying to a state where abortion is legal though.
I really doubt that the pro-life movement was deliberately orchestrated by a Republican-party conspiracy, as you seem to imply. Though I wouldn't be surprised if the Republicans identified a developing organic movement as political opportunity, which they then seized upon.
But it was not a conspiracy. It was just a plan. Conspiracy is collusion to commit a crime. Cynical politics is not a crime.