I think you're reading it wrong.
They don't *talk* about midichlorians, but it's mentioned on one of Lucas's original notes in the back of The Making of Star Wars (hardcover-only I belive).
Anakin getting to know the emperor, and slowly getting twisted, and 'his wife' going to Obi-Wan, as well as them fighting on the vulcano, Anakin losing his limbs and the emperor's (who was a president/supreme chancellor before) soldiers pick him up.
That's all there. It's pretty surprising how much *was* thought up before, even if the details vary.