The Liberty Street blog at the NY Fed says we should hope that China keeps growing:
Would a Stronger Renminbi Narrow the U.S.-China Trade Imbalance?, by Matthew Higgins and Thomas Klitgaard, Liberty Street Economics: The United States buys much more from China than it sells to China—an imbalance that accounts for almost half of our overall merchandise trade deficit. China's policy of keeping its exchange rate low is often cited as a key driver of that country's large overall trade surplus and of its bilateral surplus with the United States. ... In this post, we examine the thinking behind this view. We find that a stronger renminbi would have a relatively small near-term impact on the U.S. bilateral trade deficit with China and an even more modest impact on the overall U.S. deficit. ... To close the gap between them, a stronger renminbi would need to markedly raise U.S. exports and/or lower U.S. imports. Although we do not believe that this adjustment is likely in the near term,... the bilateral balance can be expected to shrink over the long run—owing largely to forces other than the renminbi. ...
U.S. imports from China currently exceed U.S. sales to China by a factor of 4 to 1. The implication of this ratio is that exports to China need to grow four times faster than imports merely to prevent the bilateral trade gap from widening. Can the bilateral trade deficit ever shrink, given this daunting math?
Yes, we think that the gap will shrink—but primarily as a consequence of the high rate of economic growth in China. We have already seen U.S. exports to China grow at a 20 to 30 percent pace in recent years, driven by the rapid expansion of that country's middle class and the resulting increase in demand for higher-end goods and services. We expect a similar pace of export growth for some time. A stronger renminbi could play an important supporting role in this process, even if it would not be the main driver. At the same time, the current share of Chinese goods in overall U.S. non-oil import spending—about 25 percent—is already so high that Chinese producers will find it increasingly challenging to make further gains in market share. Within a few years, growth in U.S. purchases from China is likely to settle at the much lower rate of growth seen in overall U.S. import spending.
"Within a few years" seems optimistic.