[E]verything in the reasoning of the founders pointed inexorably toward the incompatibility of liberty and equality with slavery... - Allen C. Guelzo

What the Democratic Party has most liked to say about itself—that it is the party of the working man, the voice of the oppressed, the tribune of the people—loses some of its strut in the light of a rather long list of inconvenient facts, chiefly having to do with slavery and race. Such facts as these: that the Democrats were the party that championed chattel bondage, backed an expansionist war to expand slavery's realm, and corrupted the Supreme Court in order to open the western territories to the cancer. The party's Southern wing then led the nation into civil war in defense of slavery while its Northern wing did its best to stymie the administration of Abraham Lincoln, widely regarded by the Democrats as an accidental, even illegitimate, president. Thereafter, the party embraced Jim Crow as slavery's next-best substitute, elected a president who imposed segregation on the federal workforce, and remained the chief opponent of racial equality...

[O]ligarchy, strictly speaking, is a regime "in which a rich minority rules for the advantage of the rich minority and in which the people composing that political society are ranked...because the ruling principle of that regime is the principle of natural inequality." Aristotle called it a deviant form of aristocracy (in the same way that tyranny is a deviant form of monarchy), and in practical terms, it exhibits its form through excessive concentrations of property in the hands of a few, the reservation of education to the elite, and the organization of government to serve the purposes of the oligarchs.

Where a republic demands equality, and equality tends to ensure mobility, oligarchy is about hierarchy and stasis.