You're meant to fear black shirts kicking down doors and beating people who go against the regime, but what the Left really seems to fear is that she'll be successful in delaying or halting their Great Reset plans. More than jackbooted thugs, the Left fears Meloni's ability to stifle their agenda to establish a global, collectivist oligarchy.
Postmodernism is a philosophy that refutes the notion of objective reality. It refutes the Enlightenment notion that Man advances his situation mainly though reason. Enlightenment philosophies are the basis of modern Western democracies in general, and of the United States in particular. Enlightenment thinking stands in the way of establishing a collectivist Utopia, and so must be supplanted in the body-politic by the post-modern viewpoint. Postmodernism can be said then, to be the philosophic means to that collectivist end.