WASHINGTON (CNN) – An old rivalry flared up again at the annual Values Voter Summit on Friday, when Mike Huckabee took aim at the health care system in Massachusetts that was implemented in 2006 by then-Gov. Mitt Romney. Huckabee — who did serious damage to Romney's presidential hopes last January by winning the Iowa caucuses and has made clear his disdain for the former Massachusetts governor — told the crowd at the conservative conference that the Bay State health care system is a model for the kind of government-run health care President Obama wants to implement. "It's going to bankrupt...