What the hell did Ruth Bader Ginsburg mean when she linked abortion and eugenics?

From the U.K. Telegraph: The mainstream media have been incredibly slow to pick up on a creepy comment by Supreme Court Justice Ruth Bader Ginsburg in a New York Times interview published today but flagged last week. In it, Ginsburg talks about Roe v Wade, the 1973 ruling that legalised abortion:

Frankly I had thought that at the time Roe was decided, there was concern about population growth and particularly growth in populations that we don’t want to have too many of. So that Roe was going to be then set up for Medicaid funding for abortion.