I don't think "taking underground" is the right metaphor, but it intensifies polarization, and makes these people feel persecuted. It's not that they care about the flag that much for most of them. It's that suddenly, it's not even allowed anymore and they don't agree with that. Frankly, I couldn't care less about the confederate flag, but the thought process here is very relatable.

And then these people vote. People who feel (rightly or wrongly) persecuted tend to lash out, whether it's by breaking statues or electing far-sides candidates.

Somehow this reminds me a lot of the "don't stuff beans up your nose" rule on Wikipedia.

I'd say the opposite; it's the openness in the first place that is polarizing.

The current polarization happened before Microsoft stopped letting you make racist cars