Gore could conceivably win. People forget, Dukakis led Bush by 17 points at one point in 1988 and Atwater won't be able to dig up dirt on and attack Gore the way he did Dukakis, plus Gore had a center right voting record at that point (environmental issues aside), so you can't smear him as liberal or smear liberalism itself to the extent that it was smeared with Dukakis.
Except that Dukakis made a lot of costly missteps during the campaign that hurt him at least as much as Willie Horton, especially the tank and the death penalty question in the debates. More importantly, Bush 1 took the lead in the polls after the GOP convention, about a month before the original Willie Horton ad debuted.