What is Massachusetts Liberal?

Legal Definition
Massachusetts liberal is a phrase in American politics which is generally used as a pejorative political epithet by Republicans against Democrats who are from the Commonwealth of Massachusetts. It was most significantly used in the 1988 presidential race by Vice President George H.W. Bush against Governor Michael Dukakis, and again in the 2004 race by then-President George W. Bush against Senator John Kerry. The Democratic candidates (Dukakis, Kerry) lost both races. In the Republican 2012 presidential primary election Newt Gingrich used the phrase repeatedly against Mitt Romney, the former Governor of Massachusetts, whose main residence was a mansion in the state. Romney went on to win the nomination, but lost the Presidential election.
-- Wikipedia