From The Penguin History Of Latin America, by Edwin Williamson (Penguin, 2003), Kindle pp. 135-136:
By the very nature of its foundation, Spanish American society was seigneurial and status-ridden, yet it lacked the means effectively to institutionalize differences in social status. The creole élites had to fall back on less well-defined symbols of status – landed wealth, racial purity and reputation. The standing conferred by landownership can be appreciated by the fact that merchants and mine-owners, once they became sufficiently wealthy, would invariably purchase a hacienda in order to acquire social prestige. This applied also to officials in Crown service. Yet, as we have seen, haciendas were not financially secure enterprises, and so whatever nobility a landed estate conferred could be lost through financial ruin.
A white skin was an indispensable qualification for nobility, for any taint of Indian or African blood would just as surely diminish a creole’s status as suspicion of Jewish ancestry compromised the nobility of a peninsular Spaniard’s lineage. Medieval Spanish concepts of ‘purity of blood’ were thus transferred to the Indies, but given new meaning in a markedly different racial environment: whiteness distinguished those who belonged to the race of the conquerors from the conquered or the enslaved. Hence the obsessive interest shown by American Spaniards in classifying and ranking the various permutations of race (see below). But even racial purity was an unreliable guide to social eminence, for by the late seventeenth century miscegenation had become so widespread that very few families of hacendados were totally free of mixed blood. Since whiteness was no longer a sufficient criterion of superiority, it had to be supplemented, or the lack of it compensated for, by other symbols of social quality – the most powerful of which was the pedigree or reputation of a family.
The surest source of reputation was mando, the power to command subordinates and bestow favours on clients: it was the closest a socially eminent creole could come to the condition of the European aristocrat who had rights of jurisdiction over vassals. Mando was necessarily more diffuse and could be exercised in different spheres. Thus, the higher clergy, the great mine-owners and the very wealthy transatlantic merchants possessed mando and could belong to the upper class. The hacienda, in a sense, was an accessory of mando, not its source; it was the theatre in which a man of authority, whatever the origins of his wealth, could represent to others the extent of this authority in the number of his dependants, clients, retainers, servants and workers. Because it lacked the true stamp of royal approval, nobility in the Indies was highly gestural and charismatic – a matter of striking the right attitudes through lavish acts of generosity, disinterested hospitality, conspicuous consumption or displays of gallantry and honour. Thus the ‘non-economic’ behaviour of the creole upper class – taking out a large mortgage for no other purpose than to endow a chapel, say – was no arbitrary indulgence, but a social performance whose object was to advertise social rank.