To understand Mitt Romney, you have to understand the most difficult passage of his political life: how he changed his position on abortion. Not the story he tells about it, but the real story. Romney began his political career as a pro-choicer. In the story he tells, he had an epiphany, a flash of insight, and committed himself thereafter to protecting life. But that isn’t what happened. The real story of Romney’s conversion—a series of tentative, equivocal, and confused shifts, accompanied by a constant rewriting of his past—paints a more accurate picture of who he is. Romney has complex views...