William Saletan reviews the record:
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 and a talent for framing them either way, depending on his audience. He values truth, so he makes sure there’s an element of it in everything he says. He can’t stand to break his promises, so he reinterprets them.