What if there were either a greater number of U.S. Presidential Dynasties, or long-lasting ones?
How about making the Presidential Dynasties so ingrained in the mind of the average U.S. citizen that by the present day, they are treated as a kind of noble class?
What if this removes political parties, while creating feuding "noble" parties?
Of course, since this is the U.S., it would be a more equal-opportunity noble society, but what would be the ramification?
Finally, in a few pre-1900 (unrelated) TLs, I've seen a sort of "nobility-by-examination" system, wherein peasantry of sufficient skill (or in the U.S.'s case, the average person who got lucky) are invited to join the noble class, instead of creating a new merchant class. Could this work with the U.S.?