In 1984, TN was more Democratic than the nation as a whole. I guess Al Gore's reverse coattails and Carter's residual Southern strength played a big role. In 1996 NJ went from a small Clinton win in 1992 which was to the right of the national average, to a Clinton landslide in 1996.
Gore winning all counties, including eastern ones like Sevier probably helped lift Mondale quite a bit down there. This overperformance explains why TN was the only state to swing R in 1988. As for NJ, one could argue Perot took more Clinton's "need for change of leadership" votes up there as well as residual suburban strength for the GOP that was still around 4 years after the Willie Horton attack ads.