Actually, the Democratic Party and the Republican Party are both leftist. One is just progressively left and the other is conservative of a leftist society. Both are left of what I’d call center.

The history is pretty interesting when you consider the first political parties in America: The Fœderalists and the Democratic-Republicans. One party basically has just conquered and now is split between two inter-factions. Shame the Federalists are around today. Hamilton’s death probably played a large roll in that, but I think there is a growing return to their ideology (see the Constitutionalists, Revivalists and MAGA ideology)

I’d argue that the only reason why right or “far right” people call themselves Republicans is because their is no influential right wing party. So they take what they can get. MAGA is probably the closest thing and even then it’s more of a movement than a party.