The disorder in Italy permitted the Fascisti to mount military-scale attacks on socialist municipal governments. I see no signs of anything similar in opposition to Mamdani. There is no right wing paramilitary that could invade Manhattan with impunity. It looks more like he is being left alone almost as a laboratory experiment.

Which leads to 2, can municipal socialism deliver the basic goods needed by city residents to secure its popular base? Mamdani can probably get the garbage emptied and the snow plowed, but can he impose public safety without alienating his progressive core supporters?

The world will be watching with interest.