Part of what made the scandal so damning was
the photo, if there's no Donna Rice, then it's way less damning. But there are other issues, he had been tailed by a PI before staying the night at a woman's house, he had some kind of weird stuff (changing his name in college, for example) that could cause him to kind of look like a flake. Furthermore, he actually had a strong charge against Dukakis when he got back in the race, but reports of his unpaid debts from 1984
ultimately crushed his momentum. So, assuming no Donna Rice, he takes a hit on the flake issue and 1984 debts, but I could still see him being the frontrunner. Atwater is still going to find an issue to race-bait on though, 1988 wasn't the only cycle he did that, and there's going to be some Senate vote that Atwater is going to blow out of proportion and drive certain people to the polls.