Again: after two terms of the vastly overrated and polarizing Ronald Reagan (1984 landslide notwithstanding - that was irrelevant by 1988) and Democrats retaking the Senate in 1986, the burden was on George "Wimpy Lapdog for Reagan/Ford/Nixon" Bush to win the Presidency in his own right without distancing himself from Reagan too much while at the same time, providing his own version of the "vision thing."
George H.W. Bush was, needless to say, not a very smooth campaigner, certainly not a natural (as 1992 painfully revealed for him). And again: Iran-Contra was still very real and very fresh, and he was directly caught up in it, despite his protests to being "out of the loop"*
*(Yeah HW Bush, everyone certainly believed that you - a Vice President whose resume included CIA director, Ambassador to the UN, Presidential Envoy to China, member of Congress - not to mention, being a multi-generation Skull and Bones alum and the son of a US Senator/confidant of Allen Dulles - were "out of the loop" of all of that skullduggery in the 1980s that included the highest levels of the National Security Council and the CIA in the administration of a senile B-movie actor who had no pre-presidential foreign policy experience. Uh huh.
)
At the very least, Dukakis or any other Democratic candidate should have given "Poppy" a run for his money. Pretty embarrassing result in 1988.