Why haven't any states gone the unicameral, parliamentary route?

[Vosem]

I think "republican form of government" simply mandates no monarchy and some degree of voter control; it would allow for states to have a Prime Minister. I think the Westminster model was originally developed explicitly for constitutional monarchies and it was only adopted into a non-monarchical framework by (I can't think of an earlier example) the French Third Republic, by which point most of the United States had already adopted their constitutional model and further states being admitted didn't want to rock the boat. The US also had a period of trendy uniformization in politics during the mid-20th century. States are not required to have fixed-term elections, except perhaps by their own Constitutions; I can't imagine why it wouldn't be constitutional to have gubernatorial elections called only when the state legislature votes no confidence or something, as long as some aspect of the system is elected regularly.

The primary system, which became entrenched in the United States after the Progressive Era, makes having more than two parties, like parliamentary systems do, seem redundant. Why the Progressives went for primaries instead of some other system of reforming the parties extant at that time is an interesting question that would also get at why American democracy seems to have rules so different from all the other First World democracies, even including the other presidential ones.

[Kingpoleon]

Every single one of these answers ignores the ones who stop this. It’s the same people halting the process at the federal level, and they’ve been doing it for a century and a half.

Friends, countrymen! Ladies and gentlemen! You may recognize these names halting parliamentary and other innovative democratic governments at the state and federal level; tonight, I present to you, the Republican and Democratic Parties!

[pikachu]

A parliamentary system seems to a bit outside the mind of American political imagination, but I’m surprised there hasn’t been any movement at the state level to abolish upper houses or change how they’re elected. Atm, most upper houses are effectively just redundancies of the lower house, with some of them representing the exact same districts, just for longer terms. It makes sense to either abolish them or at least change how they’re elected – use PR, experiment with multi-member districts, or something else. It’s so pointless to have two houses representing the exact types of constituencies.

Also, with the nationalization of state elections, it’d be interesting to see if some political entrepreneurs would be able to set up new state-level third parties. There are definitely states out there where one party’s national brand has become so toxic that starting a third party might make more sense.