It was neither; it was the PR people from two individual teams who told their own drivers to avoid being seen with the NRA logo. It was not a Nascar statement, nor was it an ESPN statement. The whole thing is about individual teams choosing to try to stay out of the controversy, possibly due to sponsorship concerns. Look around and see which product sponsors are more likely to be worried about the political fallout and you will have a clue to which teams it was. Either way it was their decision to make and NASCAR had nothing to do with it.
So, are we going to see NRA members required to use different drinking fountains, separate restrooms, and seated in different parts of restaurants in the near future?