That really was kinda the explanation, nobody in the stories really thought they were racist because it was only during the games. Then they'd go to work or whatever and well, you weren't racist then. Even though you'd be screaming about lynching the coworkers kid the night before.
Oh, BUSING, the reporting and stuff on that is the other thing this was reminding me of. Especially the one documentary in Boston. They weren't racist, no issues with blacks or anything, they just didn't want their kid going to school with the darkies or having a darkie in their school. So they were justified to level up the racism to stop it before dropping back down to "not-racist".