I think he tried to get an annulment rather than a divorce, but I don't know if he succeeded. I also think it's true that they were separated for some years and he dated some famous models/actresses (Morgan Fairchild, I think?) while they were still married.

I do worry that some of this dirt will stick to him eventually. It was never in the right wing's interest to stir up the dirt on candidates too early. They may be waiting until he is the nominee to really let the mud fly. So I hope this stuff doesn't stick to him, but I wouldn't bet the farm.