The most potent of China's "weapons of job destruction" are an elaborate web of export subsidies; the blatant piracy of America's technologies and trade secrets; the counterfeiting of valuable brand names like Nike and Chevy; a cleverly manipulated and grossly undervalued currency; and the forced transfer of the technology of any American company wishing to operate on Chinese soil or sell into the Chinese market.
Each of these unfair trade practices is expressly prohibited both by World Trade Organization rules as well as rules established by the U.S. government, e.g., the Treasury Department has sanctions against currency manipulation (which, alas, the Obama administration refuses to use against China despite campaign promises to do so).
The only "candidate" who understood this was Trump. Navarro doesn't point to a replacement, but knows we need one.