Former governors Howard Dean and Jim Douglas traded arguments and laughs during a lighthearted debate over a constitutional amendment for a four-year gubernatorial term. Gov. Dean, a five-term democrat and his successor Douglas, a four-term Republican, squared off for the better part of the morning at the DoubleTree Hotel on Monday. The event, a legislative breakfast series, is put on by the Lake Champlain Regional Chamber of Commerce and was keynoted by Gov. Shumlin. Over 20 sitting Vermont legislators, business leaders and others filled the 200-person space. Shumlin largely stayed out of the debate, other than to quickly side with his democratic colleague in support of the current two-year limit.