The united states is a republic whos purpose (in contrast) is "protect the minority of the opulent against the majority. "
As for externally the US does not have a track recorded of democracy promotion. My primary source is of course Noam chomsky but you can find research on this pretty much everywhere.
"While the U.S. claims to have a tradition of “promoting democracy” in Latin America, justification for U.S. intervention has been questionable and inconsistent. U.S. support for Latin American regimes has coincided with favorable economic policies rather than with the strength of democracy within a country"
https://commons.emich.edu/cgi/viewcontent.cgi?article=1147&c...
EDIT: clarification.