de facto if not de jure
This phrase is like my biggest history-related pet peeve.
How so? It's pretty much the perfect way of describing a situation that exists without formally being introduced, such as an aristocratic heirarchy that doesn't exist in any formal form but is quite real.
That's what de facto means by itself. It doesn't need "if not de jure" thrown behind it every single time it's used.
In this case, however, it could be a legitimate construct; the "if not
de jure" implies the existence of social and legal recognition of wealthy Southern colonial landowners as an aristocratic class. They considered themselves to be gentry (that is, people just below the cusp of outright nobility in the social strata); they were largely descended from groups of well-off and well-known colonists like the
First Families of Virginia, and they tended to both socialize and marry within relatively narrow social circles. Likewise, a not-insubstantial portion of the legal codes of the region were devoted to securing the stability of the American gentry, as well as kicking the ladder away to prevent both blacks and poor whites from climbing.
The wealthy families of the late 1800s were
de facto aristocracy, but in the pre-Revolution colonial south, the gentry class was fundamentally an extension of British aristocracy (indeed, early on it was not uncommon for the leader of a given community to be "well-bred" and wealthy).
If it walks like a duck, quacks like a duck, and dominates the socio-political landscape like a duck, it's probably a damned feudalistic exploiter that needs to be a head shorter.
Ninja'd. But yes, in this instance, it's completely reasonable to suggest that colonial Southern landowners were aristocrats both culturally and behaviorally as well as socially and politically.