Free birth control and abortifacients?

The blogger at Grim's Hall wonders where did the obligation arise to provide free birth control and abortifacients? "The argument seems to be that birth control ought to be free (and indeed it is, in the form of abstinence, a form of birth control that Catholics consider it a virtue to materially assist:  but I digress)." Read more here: http://grimbeorn.blogspot.com/2012/02/where-could-such-obligation-arise.html
One of the commenters there had this to say: "Walt Kelly once had Porkypine observe "I notice that all those folks favorin' birth control made sure that *they* got borned, first..."