Wallace voters tended to be poor. Actual KKK members probably voted for Wallace. Nixon appealed to wealthy Goldwater voters who, even if segregationist, didn’t care for Confederate flags or Robert E. Lee statues. Nixon voters never again voted Democratic while some Wallace voters voted for Carter. In fact, Wallace himself endorsed Carter, as did Eastland.
Southern Senator is an expert on this.
A proportion of Wallace voters probably voted for Mondale, Dukakis, Clinton and Gore.
Nixon voters if suburban and wealthy/middle class stayed loyally republican, however if more rural and in unionist areas some of them switched over for Clinton, Carter and even Gore.