The "middle class" historically are bourgeois. They're the "middle" class between the peasantry and the nobility. Since the bourgeoisie supplanted the nobility as the global ruling class, "middle class" has mostly just turned into vague self-identifier of relative income among liberals. American minimum wage workers and millionaires both broadly believe they're "middle class" while everyone with less accumulated wealth is the deserving poor and anyone with more is the decadent cosmopolitan elite. Neither will consider what that implies about the relative wealth and income of most Americans compared to the majority of the world, because of course, only imperial citizens are "middle class" (free, democratic, good, etc.) and everyone else in the world must either be primitive savages who choose to live in squalor, or brainwashed subhuman bug-people whose collectivist totalitarianism is threatening America's ability to produce this "middle class" lifestyle for an increasingly small minority of humanity.