There was one poll showing Michael Dukakis with a 14 point lead in 1988, but that was much higher than the polling averages of the time. In 1988, painting a Democrat as a liberal who was soft on crime could be a very effective ploy. George Bush started gaining ground in large part to the Willie Horton ad and other similar ads which accused Dukakis of granting furloughs to violent felons. Among other things that the Bush campaign manager, the notorious mud-slinger Lee Atwater, used was spreading rumors among the conservative media of the time (Robert Novak of CNN, William F. Buckley of the National Review) was that Dukakis had been treated with electro-shock therapy when he was in his 20's. Just before his death from cancer in 1991, Atwater called Dukakis and apologized for these tactics. The documentary "The Boogie Man: The Lee Atwater Story" details these things very well. The 1988 presidential election campaign was very ugly - mostly because of him.