Mitt Romney was polite as he took his seat in coach next to Carolyn McClanahan of Jacksonville, Fla., on a recent Delta flight to Boston. He thanked her when she said she appreciated his efforts to reform health care as the governor of Massachusetts and even posed for a photo with her. As a physician who heads a financial planning company and prides herself on having read every page of President Obama’s health care reform bill, Ms. McClanahan, 47, recognized that it’s not every day you’re seated next to a presidential candidate on a two-hour flight. According to Ms. McClanahan,...