The sentence really doesn't make sense.
Maybe you could make sense of it in some Freudian, psycho-dynamic way -- Obama was so afraid that he might have been aborted, that he rigidly clings to a pro-abortion stand as a way of suppressing his fear and rage -- but that's kind of a stretch, and it takes us into Freudian territory where anything and its opposite can be the same thing.
The key word, though, is "ancecdotal." Is it just some wild Internet rumor, or is there some basis for it? If it were true how would such a story have become public knowledge? Is it really more likely that someone would have heard a true story and circulated it, or that people are just repeating speculation and unfounded rumors?
Or maybe: "If abortion was legal, cheep, available and frequent, and I didn't get aborted, that means I must have been wanted at some point (even if that was only before anyone actually saw my ugly face)."