That doesn't mean he's controlled opposition, it means he's a social-democrat who's experiencing the limitations of what you can do within the structures of the capitalist state. This is why Marx and Lenin empasize the necessity of breaking down the old state, and building a new one.
The police of the old, bourgeois state will not simply accept a progressive leadership, it will continue to act against the interests of the working class, whoever their ofiicial boss is.
A similar thing just happened in Germany: Die Linke won the Berlin state elections. Their platform included that the growth of the police budget should stop, and there are now multiple newsstories going around filled with anekdotes about how they won't be able to do their job under a Die Linke administration.
This behaviour is to be expected of the police in these circumstances, it does not mean Mandani is secretly controled by the CIA.