Why do you think even the pro-democracy forces in China see the US's support of "democrats" as a farce? Why do you think the images in HK of protestors with the US flag were seen as nothing short of treason, even among the liberals of China? The hypocrisy is so obvious, and the naked self-interest too glaring.
The US's foreign policy has set back the cause of democracy and liberalization in China by decades with its underhanded shenanigans. To recieve their support, even moral support, is the kiss of death in China.