The US has been facing the same problem that every superpower faces. We benefit from a stable global geopolitical climate, so any move that rocks the boat is bad for us. That's why every president until Trump has been reluctant to truly bring out the big guns with China. Those guns hurt us as much as China, and Trump is feeling that now. His trade war with China has wiped out most of the economic benefits of his big tax cut legislation.
Previous presidents weren't hapless morons on this issue. They just realized that we don't have many strong cards to play here. The TPP was the best card we had, but frankly I was pretty skeptical of how effective it would be. I'm similarly skeptical that Trump's strategy will be effective. China can easily afford to wait him out.