Its a scary thought and the transition would be chaotic. Think about how bad the healthcare.gov website was even after they spent to 2 billion dollars on it. People would be buying up real estate and other assets with their cash. Their would also be a run on silver and gold coins to fuel the underground economy maybe even copper coins! The difficulty of getting into crypto exchanges would funnel all the wealth into govcoin but I don't think the American public would give up their cash without a fight.