Earlier quoted context omitted.
It's definitely not this simple. How would you execute an exchange ban politically? Any politicians who did this would be responsible for instantly vaporizing tons of value owned by an increasingly non negligible fraction of the population that spans a broad spectrum of political affiliation. An exchange ban also wouldn't stop bitcoin, because the network would still continue running and anyone cutoff and stuck with…
I don't really want to see politicians giving bitcoin holders too much weight when making decisions about how the economy should function. Anyone who owns Bitcoin is gambling. There was never a guarantee that value would go up, or that the government squash the idea entirely. If we as a society decide that Bitcoin is too dangerous, current holders should accept Bitcoin for what it was: a bad investment.
There are at least a couple of bitcoiners currently in Congress, including the new Senator of Wyoming who is publicly all aboard the idea that bitcoin is an important, long term store of value that the US needs to jump on board with.
How many politicians do you think already hold some bitcoin quietly, just in case?