Of all the culture-war issues, the endless battles over gay marriage and immigration and so on that divide liberal Left and conservative Right, abortion is surely the most bitter. You can see why, or you should be able to. It places utterly implacable moral imperatives against each other. For one side, it is straightforward murder. For the other, it is tied up with every human's right to do what we want with our own bodies. Large parts of both sides are completely incapable of seeing the argument from the other perspective. They may as well be speaking different languages.
And, human nature being what it is, we tend to ignore stories that don't fit our favoured narrative; it's an established and well-known psychological phenomenon called confirmation bias, which essentially comes down to Simon and Garfunkel's "a man hears what he wants to hear and disregards the rest". So horror stories of dangerous backstreet operations in countries where abortion is illegal are ignored by the pro-life side; horror stories like the Kermit Gosnell atrocity are ignored by the pro-choicers. And scientific...