Sure, they may have known that "defund the police" couldn't last, but during the summer of 2020, progressive politicians took it seriously enough in public (much of it due to BLM). We got CHAZ in Seattle, Antifa trying to burn down federal buildings and police stations, and progressive DAs (e.g., Chesa Boudin) at the time decided to severely reduce the penalties that they would pursue for even serious crime. A few cities even got around to attempting to redirect funding from police to social workers and the like. Progressive politicians continued to take "defund the police" seriously until the fall, when it was clear that the issue had turned an easy election for Biden into a close election that he was at significant risk of losing. All of this indicated to criminals that law enforcement would be much lighter, which is why crime skyrocketed during that time and has continued to stay elevated until this day