[dragonwriter]

That group is, in fact, traditionally considered largely working class (proletarian, more specifically the proletarian intelligentsia, though some in that group might be middle class, again, in the traditional class analysis, petit bourgeois sense.)

American popular usage defers from traditional economic role-based class analysis to be instead do income-based “class” terminology which instead of defining the middle class as the petit bourgeois who apply their own labor to their own capital in production (or otherwise have a relation to the economy which depends on both applying labor and ownership of the non-financial means of production) defines middle class as the segment around the median income, almost entirely within the traditional working class.

This is a product of a deliberate effort to redefine terminology to impair working class solidarity, not some kind of accident.

[jazzyjackson]

Whose tradition? Not the American working class. Despite the strong labor unions extent I think you'd be hard pressed to find marxists among them. We talk of middle and upper class precisely because we don't ascribe to the "traditional" framing of bourgeoisie v. proletariat, because running a business is actually work too, even if you own the capital. If you sit around and spend money all day we just call you an aristocrat.