How, when, and why did Mitt Romney change his mind about abortion? William Saletan delved 50 years back into the GOP front-runner’s personal history to uncover a well-documented pattern of shifting stories and positions on the issue. Saletan will be chatting with readers about Romney’s core malleability, what it says about the candidate and what it means for the 2012 presidential race. Bring your questions and comments about Romney’s pro-life conversion to Slate’s Facebook page on Thursday at 2 p.m. ET.