Why wouldn’t they? It works. There are tons of left-leaning people who, despite disagreeing with literally every plank of the current democrat platform, still remain staunch democrat voters because the alternative has been successfully branded as racist. Even most republicans would rather forsake every principle they purport to hold than be accused of racism. The entire point of the accusation is to turn all opposition to leftism into radioactive persona non grata, and It’s a strategy that continues to work.