I think this is truly an act of desperation for America; it sees Chinese success and just wants to copy what it can without real analysis. It thinks that a population match would allow it to overcome China's advantages but actually, a large, mismanaged population will be like India. China's strength is in the intellect and ambitions of its people, in Chinese parents chasing the best education possible for their children in STEM subjects at any cost. China rises because Chinese culture has made it the ultimate honor to achieve academic perfection. Americans have gotten fat and lazy, long used to being on top. Americans want to be literature, management, business, arts, communication majors (all fields that draw laughter and quiet derision from peers in China) because they seek the easy way out, and the American system was made to give it to them. An American with a bachelors or masters in management can make more money and attain higher corporate rank than the foreign PhDs who work under them powering American innovation.
America's strength is in luring foreigners to its lands with promise of easier life. That easier life is only achievable because America has a high resource to population ratio. If you triple that, then the stresses of life and affordability of common goods will increase and decrease America's allure. No Chinese would move to America and work in an American lab just to live a similar lifestyle compared to what he had in China except he gets to experience language barriers, cultural shock, racial discrimination, etc...
America's problem is in its culture growing lax and becoming increasingly dependent on foreign talent; if it ignores that but just fills its country with more of the same people, it will cause another problem while failing to address the first one.