Decolonial Marxism combines ideas from Marxism, which focuses on class struggle and capitalism, and decolonization, which challenges the power structures first imposed by colonial rulers.
Settler colonialism is a type of colonization where a group of people, called settlers, come to a new land and stay there, taking land from the Indigenous people who already live there.
The notion of a “middle” class is just another way of saying an “ideal” class. In our case, this refers to the mode of living brought to these lands by genocidal settler colonists.
The Nazi project can be understood as a form of settler colonialism, centered around a similarly aggressive expansionist agenda for Lebensraum (living space) as their manifest destiny.
The Nazis referred to themselves as the Third Reich. They got the idea from a book by that title in 1923 that wanted a bigger and better colonizer version of the First Reich.