Who performs better in general elections? Moderates like Bill Clinton, Schwietzer or Warner would attract a lot of GOP-leaders and independents. But they wouldn't get as much base excitement as liberals like Dukakis, Dean, or Obama. Who, historically, have performed better on the nation level?
As a MA resident during Dukakis' term as Gov I can tell you he was no more liberal than Clinton. He was basically a technocrat. What is true is that he was unable to deflect that charge of liberalism from the well executed '88 campaign of GHWB.