US politics has been highly polarized at both ends of its history except the early-mid 20th century when the Dixiecrats ran one party states in the South. The rest of the country was contested in relatively free elections, so the GOP and liberal Democrats split the seats between them. Then the Dixiecrats & liberal Democrats formed a Congressional bloc consistently controlling about two thirds of the seats.
1/
No one of the three factions could pass anything by itself nor hope to gain a majority, so coalition or compromise were the only strategically valid options for party leaders to pursue. But with a coalition of nearly two-thirds, they could very easily pass laws on matters that the coalition agreed about. Furthermore, the coalition was formed of only two factions, so coordinating the factions was relatively simple, much more so than for the many-party coalitions that sometimes occur in countries with proportional representation.
So this period was characterized by high levels of compromise, and political depolarization between the parties.
2/
But of course it was all built on terrible injustice. The civil rights movement fought for & won a great moral victory, for which we as a country can remain proud, & we can honor their struggle.
We can simultaneously recognize that in restoring relatively free elections to the South, the reforms set the stage for re-polarization. There are always side effects. Unfortunately, polarization in our political system makes the system work terribly. I think we can lay part of the blame of our current political disaster on the political consequences of polarization.
3/
So it's worth thinking about what further reforms can mitigate the harms of polarization -- but without anything like the terrible injustice that 20th century depolarization was built on.
Fortunately, I think there's a simple answer: Bring back a three-party system with three roughly equal parties. That will bring back the requirement for compromise plus the huge, uncomplicated coalitions that make governing possible and effective under our Constitution.
4/
The two-party system is created by our voting methods. Rather than ranking or rating or approving candidates, we are only allowed to vote for one, and only one candidate wins in each district. Strategically this forces voters to collect into two parties and fight over the median voter. You've probably heard about voting reform proposals to rank or rate or approve multiple candidates.
I propose instead: Vote For One, Top Two Win. Strategically, this forces voters to collect into *three* parties that all fight to pull voters from each other.
5/
The other big wrinkle in the US is of course the Presidency. Only one Presidential candidate can win under the constitution, so that strongly pushes national politics to a two-party system regardless of the voting method. Even with rankings, it's necessary to win the majority, and it's fighting for a bare majority that motivates a two-party system.
What would work? We could require states to award half their electoral votes to each of the top two Presidential candidates in the state. That would make it a true 3-way contest.
6/
This is not an idealistic reform. I'm sure few people will like it, because they prefer something more idealistic.
Its chief advantages are:
• No Constitutional amendment is required.
• It only requires extremely minimal changes.
• We know from our country's history that it would create both effective government and depolarization.
• It maximizes the proportion of people who are represented in the governing coalition (two thirds of voters, rather than half, will get their way).
8/8
The US Constitution has a quirk that would come into play at this point. If no candidate gets a majority of the electoral votes, then the state congressional delegations choose the winner from among the top 3 candidates.
This strengthens Congress relative to the President, and further eliminates gridlock: Whichever two parties form a coalition, they will always choose one of their own, giving them a President they can work with.
7/