Something you have to keep in mind is that China is a much, much, more populated place than the USA in a smaller land mass.
I think recent times are showing an issue with protest. In a democracy, if the 'side' that 'loses' (democracy is ideally a collective decision of individuals trying to come to the objectively best decision, not a team sport trying to beat the other team - the founding fathers feared parties for good reason) decides to try to disrupt society in response, that simply doesn't work.
I think the true value in protest were sides managing to illustrate to others that support for views, that did not seem popular, did indeed have substantial support. The civil rights protests are a good example. The status quo of America was 'separate but equal'. Clearly many did not really believe this, but it can be difficult to express views that run contrary to the perceived majority of a society. Protest enabled these people to unify and others to feel more comfortable "coming out", as it were. In today's society, the internet serves this purpose. You can find and organize support nationally, and even internationally, for any view. This is a reason that I think having a completely free and open internet is crucial.
The Vietnam War is a good example of protests that were not useful, even though they did have a good overlap with the civil rights protests. Many people vehemently opposed the war, but many also supported it. So it turned into the sort of protest that is not about enabling people to come out (as it was already completely acceptable within society to support or oppose the war) but simply because one side was upset that they were not getting their way. There was lots of chaos caused, lots of social disruption, and it changed absolutely nothing.
Imagine the issues the US is having today, and then multiply our population by well over 400% with a proportional (if not exponential) increase in mutual antagonism. I think we're already starting to reach the breaking point of our political systems. So I think simply assuming our system and its status quo suddenly strapped onto a population 400% larger, without massive changes, is not really reasonable.