If we're saying that China has "conquered" places like Tibet and Xinjiang then surely the United States has done much worse to the entire land mass it occupies. But honestly, I'm very much opposed to nationalism so I'm not interested in historical claims, even though China's historical claims are much much stronger. What's relevant in both cases is that the United States and China both have both de facto and de jure control over their present territories.

> Hong Kong

Did India conquer itself when the British returned rule of India to Indians?

> China's CCP has been pushing out immigrants, and fostering racist sentiment

It's a little more complicated than this. I think the level of racism at both the state and individual levels is similar between China and western countries, although it may manifest in different ways.