We often hear the phrase "first they came for the [vulnerable marginalized group], but I didn't say anything ... then they came for me." Simplistic, but we have actually seen this happen repeatedly in history, where a repressive regime starts with soft targets.
We also often hear "if we don't protect Nazi speech, they'll come for [vulnerable marginalized group] speech." I can't think of any real-life examples of this, though. Can you? Please advise!