Counties can flip because of people turning 18, dying, turning out, not turning out, moving in, moving out, etc. All of that is distinct from an individual voter flipping.
Yeah, I have to agree. Obviously some people flipped from having supported Dole in 96 to having supported Obama in 2012 (especially in the regions I mentionned), but I think they would have been a relatively small proportion of the population. I think Clinton 96/Romney 12 voters would have been a lot more common.
I think the story about areas that voted for Dole in 96 and Obama in 2012 is really more about the demographics having changed than anything.