I'm not even interested in the psychological manipulation angle; men are manipulated by women, as well... just in different ways. I don't believe that "women have all the power" in a relationship... that depends greatly on the particular relationship. I daresay that any woman dating Derek Jeter or George Clooney has an absurdly small amount of power.
I'm talking strictly about women choosing to bear the child of a man who already has dozens of children. These women know that he will be completely unable to support this child, and yet make a long chain of choices (no birth control, no abstinence, no condom, no Plan B, no abortion, no adoption) that lead to them being stuck with yet another "fatherless" child. In this particular area, they do have all the power... and they choose not to exercise it.
Maybe they did know that and don't care. We have no idea how these children are being raised. All we do know is that he can't afford to pay child support. For all we know these women are working and raising their children just like everybody else.
With that said - birth control, abortion and plan B are NOT accessible or affordable to everyone.
As an aside, I think Clooney (and a few others) intentionally dates powerless women. He rarely dates women that are on the same level as him. Unless of course, the rumors are true and they are all beards.