I noticed your fixation on the labor theory of value. The labor theory of value isn’t something invented by Marx, and moreover Calhoun was 40 years older than Marx and was writing his own ideas when Marx was in diapers.
Considering that David Ricardo and Ben Franklin also held to variants of the labor theory of value, they’d be Marxists as well applying your theory. They weren’t, of course, and neither was Calhoun.
http://en.wikipedia.org/wiki/Labor_theory_of_value#The_birth_of_the_LTV
Early insights in the labor theory of value appear in Aristotle´s Politics. He developed a “theory of the value of labor”, holding that the value of labor skills is given by the goods they command in the market.
St. Thomas Aquinas, based on Aristotle’s theories, produced early labor values theories. Some writers (including Bertrand Russell and Karl Marx) think the labor theory of value can be traced back to him.
Benjamin Franklin in his 1729 essay entitled “A Modest Enquiry into the Nature and Necessity of a Paper Currency” is sometimes credited (including by Karl Marx) with originating the concept in its modern form. However, the theory has been traced back to Treatise of Taxes, written in 1662 by Sir William Petty and to John Locke’s notion, set out in the Second Treatise on Government, that property derives from labor through the act of “mixing” one’s labor with items in the common store of goods, though this has alternatively been seen as a labor theory of property.
Scottish economist Adam Smith accepted the LTV for pre-capitalist societies but saw a flaw in its application to capitalism. He pointed out that if the “labor embodied” in a product equalled the “labor commanded” (i.e. the amount of labor that could be purchased by selling it), then profit was impossible. David Ricardo (seconded by Marx) responded to this paradox by arguing that Smith had confused labor with wages. “Labor commanded”, he argued, would always be more than the labor needed to sustain itself (wages). The value of labor, in this view, covered not just the value of wages (what Marx called the value of labor power), but the value of the entire product created by labor.
Ricardo’s theory was a predecessor of the modern theory that equilibrium prices are determined solely by production costs associated with “neo-Ricardianism”.
Classical economist David Ricardo’s labor theory of value holds that the value of a good (how much of another good or service it exchanges for in the market) is proportional to how much labor was required to produce it, including the labor required to produce the raw materials and machinery used in the process. David Ricardo stated it as, “The value of a commodity, or the quantity of any other commodity for which it will exchange, depends on the relative quantity of labour which is necessary for its production, and not as the greater or less compensation which is paid for that labour” (Ricardo 1817).
But your little smokescreen away from the fact that Calhoun BEHAVED exactly like a Marxist won't work. He wanted to shut down all discussion of slavery, not merely "protect it" where it existed; and he, like Fitzhugh (whom you also dodge) loved the communistic aspects of have a class that "took care" of "inferior" peoples.