White backlash is when people who are white become angry and lash out at other people who are not white, usually because they feel threatened by the changing power dynamics and roles they play in society. For example, let's say that some people who are not white become elected to government or start to become popular in some other way. Some white people, feeling threatened by this, may lash out and express their anger by protesting, voting, or speaking out against these people. This is an example of a white backlash.