Of the thousands of people who gathered in the plaza of the Old State Capitol in Springfield, Ill., for Sen. Barack Obama’s presidential campaign announcement last Saturday, only a handful were protesters rather than supporters. But there were 50 or so waving signs and chanting, “No abortion, no Obama.” Their voices might become a consistent presence as the senator makes his way around the country in his bid to win the White House. Abortion foes in Illinois, following the lead of registered nurse Jill Stanek, are targeting Obama (D-Ill.) for a number of “present” and “no” votes he cast on...