But, I don't see any US president standing for it before the election, or at least attempting to sell it to his electorate/funders, unless pretty much a hot war is happening.
USA was the biggest industrial power by late thirties, and I think no country would've stood for Germany in the open on the global arena by then. The situation is more than a bit different now.
Be hopeful that the politicians will be as logical as you are.
I don't think it would be a hard to sell the American public on some kind of rationing if Beijing suddenly embargoes the US in a way that necessitated it. Given the economic dependencies that you cite, I think a US-initiated decoupling would likely proceed slowly enough to not cause critical disruption, just higher prices.
I don't think it'd play out like that. It's been a few generations, but Americans have experience with wartime rationing that was far more extreme. They didn't riot and demand a peace treaty with Hilter and Tojo, so they could could get the consumer goods they had been used to having.
https://en.wikipedia.org/wiki/Rationing_in_the_United_States
https://www.history.com/news/food-rationing-in-wartime-ameri...