http://www.slate.com/articles/news_and_politics/politics/2015/05/america_s_best_presidents_have_been_flip_floppers_scott_walker_and_hillary.html

Every presidential election cycle has its designated “flip-flopper,” the candidate attacked for his insincerity, inauthenticity, and lack of “resolve.” In 2004, it was Sen. John Kerry, who was famously for the Iraq war before he was against it. In 2008 and 2012, it was Mitt Romney, who went from moderate governor of liberal Massachusetts to an archconservative who hated universal health care, despite his pioneering role in making it a reality.