Dale Sr. never really spoke about politics one way or the other, but it's worth noting that his son is an open progressive in an industry that appeals almost entirely to the Conservative crowd. Is there any reason in particular you think Dale Earnhardt was a typical republican?

Edit: after a little more research it seems that Dale was probably a traditional Southern conservative but not what we would call today as a MAGA conservative. An excerpt from this article reads:

Dale’s daughter Kelley recalled an incident that occurred in her childhood, when her father placed a bumper sticker reading “American By Birth / Southern By The Grace Of God” on the rear of his truck. The family’s black housekeeper mentioned that the sticker, which featured the Confederate flag, made her uncomfortable. Dale immediately took a pen knife and slashed the flag off his truck, leaving the expression of Southern pride while divorcing it from the region’s sour history.