What you are doing is “asserting the premise”.
Your premise is that Calhoun and Fitzhugh were socialists or marxists. But rather than making a case for this premise you simply write as if this were established fact. You assemble a series of facts where Calhoun and Fitzhugh appear to be in concord with Marxist belief and run with it.
In order to do so you ignore other sources of political thought that were known to influence these men (Filmer in Fitzhugh’s particular case), and you likewise ignore how their own positions contradict the positions of socialism. You ignore the fact that Marxism sees capitalism as a phase leading to socialism, while Fitzhugh was a critic of industrial capitalism entirely. The socialists weren’t trying to hold on to the pre-capitalist world of the ante-bellum South. Fitzhugh was.
Where do you find Marx or any other socialist of the 19th century defending slavery? You don’t. Not only that, but Marx was demonstrably a fan of Abraham Lincoln and the Union side in the Civil War. He was the author of that fan mail letter the First International sent to Lincoln.
Now I suppose it’s possible to cherry-pick Lincoln in order to show that Lincoln was a “Communist” at heart. Lincoln shut down newspapers in the North to control political thought, and jailed a few thousand political opponents without trial.
Like Marx he was a promoter of centralized, consolidated government. Marx advocated the income tax and Lincoln implemented one. Lincoln’s war against southern secession prefigured the Brezhnev Doctrine, once in you’re in you can’t get out. He waged a terrible war on his own country, something highly typical of the communist world.
So it’s not so hard to play this game. Look for the apparent similarities, ignore the inconvenient differences. The trouble is Lincoln never joined a socialist movement. Neither did Calhoun or Fitzhugh.
I find Marx’ articles on the American Civil War fascinating! They were written for the New York Tribune and the Vienna Presse. He wrote private letters on the topic as well. Absolutely remarkable!
It’s not a game. It’s an easy adage. If it walks like a marxist and quacks labor theory of value like a marxist, it’s a marxist-—whenever it occured.