>Are we describing China or Brexit/Trump polls from 2016.

Snark aside, there's a huge difference between the two. In the case of brexit/trump, even if there was social pressure to not reveal your real preferences to the pollsters, everyone's real preferences are accurately represented at the polls. Moreover, nobody is risking getting sent to reeducation camps or getting their social credit scores ruined by saying they support trump or brexit. This is as opposed to China where the only measure you have are opinion polls, and the only cross-check mechanism is whether the CCP is still in power or not.