The media know rape, incest and women’s issues are a minefield. They are often hoping for blood so their story gets attention. If it bleeds, it leads.......
They also know that the true views of Social Conservative Republicans are shared by a only small minority of the electorate, as well. So it's a productive field to mine.
Of course, due to media bias, Democratic candidates don't get equivalent partial-birth abortion questions in debates. But not much that can be done about that.