Elizabeth Scalia responds to Williams at The Anchoress, "“Abortion Ends Life? So What?” Here be Monsters. – UPDATED":
Williams is making precisely the utilitarian argument made by every totalitarian ideology that ever slaughtered people by the millions, because they were the wrong sorts of people, or were useless eaters, or they could not contribute to the advancement of society, or their quality of life just seemed too dubious to those who did not know and love them. Immediately after expressing concern that “liberals” might look like monsters, she utters the monster’s line: you have no rights except those I give you.RTWT.
And click through at the post for Williams' essay. Diabolical is just about right.