I think this is part of the underlying reason of this potential tariffs war / trade war. While the obvious reason of this conflict is China's trade surplus with the U.S, the more important reason, nonetheless, like many other have already suggested, is not the numbers in the surplus, but what constitutes the surplus.
To put it more bluntly, American society does not really mind a trade surplus of importing plastic slippers or other low quality goods, but people have some serious concerns about importing a large amount of high tech components from China. (I believe it is one of the recurring themes in the MIT's PIE report).
What makes it more complicated is state intervention in China, like the former Soviet model, China's current economy is evolved from planned economy. Even though under the notion of "Capitalism with Chinese characteristics" that many things in China today look ultra-capitalistic, government's involvement still plays in big role in the business sector. For example, the government's push to develop solar panels. The invisible hand in China certainly is not the hand of the "free market," but the hand of the government.
This leads to the central question of today's trade war. The American side thinks that China is taking a "manipulative" approach to global trading and taking advantage of the "free market" system of the West.
This reading is not completely unjustified. For one, the Chinese currency is heavily manipulated. (Though the Chinese side would also argue that American economy is not that "free" either, for example, through government's subsidy, etc.)
What surprises me though is the tactics used in solving this conflict. By merely highlighting the "surplus" is both misleading and dangerous. Also, China now is the second largest economy in the world now. It is ludicrous to even slightly imagine that they would not want to develop their own technological prowess. For the American side, people may think they can stop exporting silicon chipsets to the Chinese to curtail the following import of high tech components. But will the Chinese side agree on merely manufacturing plastic slippers for another twenty-years?
I think a much better approach is focusing on our advantages, and most importantly, investing in the future, in the US, that will be the areas of software, biochem, exploratory sciences, and to further strengthen the competitive edge. By imagining rolling back to the factory-age of the 60s and 70s and wishing to take back the jobs that we have already outsourced to other countries actually is a very backward mode of thinking.
