Up until fairly recently the defense of abortion followed lines of "helping the poor and minorities avoid babies they could not afford/that would keep them from an education/that would force them into dead end jobs/etc."
But if a poll were taken, it seemed most abortions were provided to middle class white women because 'the time wasn't right'.
(Usually meant the BMW wasn't paid off and there was a managers job opening)
The concept presented in the original post and in Weddington's letter at post 15 fits with the old argument. Now the "personal choice" coven seems to admit to that: maybe the movement saw the hypocrisy, maybe they realized that the welfare they also supported worked fine at assuring a continued lower class stayed in 'it's place', or maybe they just decided to admit it.
I have also been in your situation of defending Life to those who don't get the point. I have recently started sending them this website with a note to check out the RoeBots section especially. It causes a lot of angst for the Planned Parenthood set.
http://www.deathroe.com/roe_v_wade_abortion_survivors/