I must be one of those "useful idiots"

What I often find disconcerting about some individuals who post comments on pro-choice blogs is how they view the prolife movement and its intentions. For example, this comment by Dianne at Feministe:

It is in the US's interest to make people in most of the world as miserable as possible and killing and maiming women is one way they do it. Plus anti-choicers get off on the idea of women being hurt. Oh, there are people who believe that they are saving lives by preventing abortion. I suspect that the higher ups in the anti-choice industry refer to them as "useful idiots". But the average professional anti-choicer is dedicated to enslaving, maiming, and killing women. Period. There is no desire to "save babies" there.

Pushing aside the nonsensical U.S. interests bit - this is just so weird to me. Are all the professional prolife women (probably the majority of professional prolifers) dedicated to enslaving, maiming and killing women? If the main goal of professional prolifers is to do all these horrible things to women then why do they spend all this time and energy on other issues (embryonic stem cell research, euthanasia, cloning, etc.) which don't effect whether women can have abortions or not? Is all that work just a ploy to keep their cover? If prolifers want to hurt and punish women then why do most prolifers not favor the idea of imprisoning women if abortion were to become illegal? What are the board meetings of the "higher ups" like? Old, white men cackling as they plot the next way to enslave, maim and kill women?

How can people who go about working, interacting and living as average human beings think such incomprehensibly foolish things?

Is it really that hard to fathom some people genuinely think killing nascent human beings is wrong and should be stopped and because of this they dedicate their lives to trying to save those human beings?