“But if you are buying from China, whether you are a retailer who will have cheaper goods, or your are a business making capital investment (buying computers or equipment), you prices go down which is good for you and your customers. “
Doesn’t stop there...that’s not the extent of it.
If you are an American biz competing with goods coming from China, THIS move screws you and your business.
THAT’s what Trump is talking about.
You are right, but it doesn't stop there either, because if am a consumer in the US, and I get lower prices, I benefit, and I have extra money to invest or spend which either way will help. If it was all win/win to devalue, everyone would do it. The US has often been at its best (like the mid-80's) with a strong dollar, big trade deficit, and competitors trying to devalue to compete.