To clarify Marx’s theory: it assumes that the bourgeoisie are more or less the same, a relatively small group of people who hold all the economic and social power at the expense of the lower class(es) who suffer/stagnate (regardless of consideration of the addendum to address the middle class and American social structure).
I think we can all agree that Gatsby and Tom are both easily defined by Marxist critics as being bourgeoisie because of their economic wealth. However, Gatsby is seen through the eyes of the society within the novel as being NOT equal to Tom, despite being roughly equal in terms of economic power/wealth (though not in how income is received). In fact, upon discovering that Jay Gatsby was born James Gatz to a proletariat family he was degraded socially in the eyes of the characters (Tom, Daisy, and Jordan) into the same class as poor, social climbing, vulgar, Myrtle. Marxist criticism would ascribe this phenomenon as being caused by the ideology of classism (one’s value as a person is directly related to their class- proletariat/lower class inherently shifty and vulgar) which is designed to suppress the lower class(es).
My take away is that in the Great Gatsby economic status is not necessarily equal to social status. Jay Gatsby has accumulated an absurd amount of wealth, however his social status is not entirely equal. Nick Caraway clearly comes from an affluent family however he does not live a lavish lifestyle and likely does not have the same means as those he associates with, however coming from an old affluent family allows him to have a higher social status than he has wealth. Tom Buchanan who has both money and the social status of coming from a prominent background sees Nick as belonging to the same social class as him whereas he sees Gatsby as inferior (even before the affair). Marxist critical theory is based primarily on the power of economics/money however it seems to me that the Great Gatsby stresses the importance of social background and how even if one can gain/improve their economic power they will never belong to the same social class as those born into it.
What did you get from it? Do you agree or did you see something else about Gatsby and socioeconomic class?