The U.S. has a history of using gold to solve its economic problems. It deceived the world by claiming to uphold the gold standard while, in reality, printing unbacked currency.
A potential stablecoin act could allow the U.S. to pull off the same scheme again. This time, the issued tokens would be backed by U.S. government debt. However, since they wouldn't be a direct government liability, they could de-peg, just like what happened with Do Kwon's UST stablecoin from Terra (LUNA)