Manufacturing is about 14% of the US economy, with maybe 5% of that 14% vulnerable to Chinese competition.
Retail and wholesale distribution are a far greater share of our economy than manufacturing.
Re-valuing the remninbi would raise prices for American consumers, increase inflation, and lower the standard of living for Americans.
The theory that a lower remninbi would decrease exports from China is a fallacy. Whatever's going over there is going to continue to be produced there, and they are not interested in buying US consumer items or even industrial items. Whatever is made here but can be made there is going to be made there due to high labor costs here, high litigation costs, and high health care costs in the USA.
Even mighty GM is getting their butts kicked in Shanghai by upstart Chinese automakers. You think GM's going to start shipping Escalades to China just because the currency is re-valued?
I probably have a bit more insight into this situation than most as I have been doing business with China for 25 years.