Which is mixed. If the dollar tanks, then that will make our exports cheaper, which is good for workers, but bad for consumers. And vice versa.
Pick your poison.
In a situation where we didn't have huge fiscal and trade deficits and oceans of our currency out there, that may hold true. This is a much different scenario, because we are in a MAD financial arrangement with China and the rest of the world. We buy their goods, they invest in our markets, propping up what should be a weak dollar, which is also the world's reserve currency and the denomination for most of the world's important commodities.
Essentially that situation has allowed us to run highly inflationary policies and more or less get away with it. Link the yuan to oil and gold and that all changes. If those become the preferred currencies, the dollar could crash to a small fraction of it's value. It won't help our imports because we won't be operating in the global market with dollars anymore, wages and prices will simply adjust to the new reality of a far less valuable dollar, assuming we don't go the way of Zimbabwe.
It will knock the crap out of our markets and banking system, and will crater govt spending to the point where I don't know if DC could hold the country together.