The proletariat is not a sociological category of people in such-and-such income group and such-and-such occupations, etc., but rather a real, historically developed entity, with its own self-consciousness and means of collective action. The relation between an individual proletarian and the class is not that of non-dialectical sociology, in which an individual with this or that attribute is or is not a member of the class. Rather, individuals are connected to a class by a million threads through which they participate in the general social division of labour and the struggle over the distribution of surplus value.
One issue that needs to be considered in relation to the definition of Proletariat is Wage Labour. Wage labour is the archetypal form in which the proletariat engages in the labour process, that is, by the sale of a worker’s labour-power according to labour-time. K. Marx considers piece-work, in which the worker is paid by output rather than by time, as a form of wage-labour, not essentially different from wage-labour. Today workers are obliged to sell their product by means of contract labour. So, what is essential in the concept of proletariat. Contract labour does undermine working-class consciousness, but at the same time, the person who lives in a capitalist society, and has no means of support but to work, is a proletarian, even if they are unable to find employment (where workers may become lumpen-proletariat if their living conditions are very difficult).
If one earns tiny wages and exists in a degraded living condition, does one leave the Proletariat world and become a Slave ? When does a consistently degrading country replace government with revolution born of old ideas in a new world? When does that flash of revolution extinguish itself and the army of new Slavers rule with an “iron fist” and no mercy? So goes the USA?