America doesn’t have rulers. It has democratically elected politicians. China doesn’t have democracy, however.

> if we were to have sincere solidarity with Chinese people against the international ruling class

There is also no “international ruling class”. In part because there are no international rulers. Speak in more specifics if you want to stick to this claim.

> Concentration camps, genocide, suppressing free speech, suspending due process

I’m not sure what country you are talking about, but America definitely doesn’t fit any of these things that you claim. Obviously there is no free speech in China. And obviously there is no due process if the government can disappear people like Jack Ma for years or punish free expression through social credit scores. And for examples of literal concentration camps or genocide, you can look at Xinjiang or Tibet.