It is hard to know where to start with this one.
First, the Jessen ad is not John McCain’s ad. Second, McCain does support the availability of abortion in cases of rape and incest (Sarah Palin does not). And third, Barack Obama voted against legal recognition to infants of quesionable viability while an Illinois state senator. Obama has yet to clarify his conflicting statements about why he said he would vote for the federal version of the BAIPA but did not vote for it at the state level.
I recently had an op-ed published in the Philadelphia Evening Bulletin on this topic: When does a baby get human rights?