I have a really good book on FDR and Chang Kai-shek, and more importantly his wife, who was instrumental and solidifying the American public's positive view toward Chang's battle with both Mao and the Japanese. There is a fair amount of revisionist history you can often find about this, but keep this in mind, not only was the administration and specifically Eleanor pulled strongly by friendly ties with Chang's leadership, so was a huge group of missionaries (of whom my Great-Uncle was one, he spent 50 years in China) who had lived in China for many decades. Those missionaries came back, or sent back, many individuals to stoke friendly relationships between Americans and the Chinese.
People in the Midwest were very devoted to this effort. Keep also in mind that Herbert Hoover was a mining expert, and missionary in China also. Probably there were very very few people in Washington D. C. that knew more about China than Hoover.