A good example to discuss is Australia, Joan.

They vote in similar fashion we do for their House of Representatives (winner-take-all) but because they vote differently for their Senate, they did not end up with just two parties. Another important distinction to mention upfront is that they do not have a president (the king does not represent a real political empowered entity).

The point of bringing up Australia is showing that once a door is opened, more doors open. Once we have proportional voting in the USA at State and local levels, we will get more parties in at the Federal level without changing the way we vote for the Federal level.

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Australia has 72 Senators and 6 States. Voters in each State vote for 6 Senators in one single election (and 6 more Senators in the other cycle).

This system is called multi-seat proportional, which means there are still districts (each State is then a district), but all 6 seats are voted on at the same time. It would have been better if all 12 were voted on at once, but 6 is better than winner-take-all.

This system resulted in the Green Party having about fourteen percent of the votes and seats (today). The two-party chokehold is therefore removed because the voters get a real chance to express themselves in more refined manners at this level due to the voting system.

House of Representatives is voted in like we do: winner-take-all in single districts. What is the result?

Low and behold, the Greens still get a decent number of votes. Once a party is seen as legit, they can wield greater importance in the other voting system as well. In this case, the House.

https://www.cia.gov/the-world-factbook/countries/australia/#government

The importance of having a third party cannot be overstated. With people capable of pronouncing their issues, needs and desires, the national debate is more than a Yes/No two-dimensional discussion and decision-making process. More will get done, and more will get done in smarter ways (less group think will occur).

That's a big win.

Voting is compulsory in Australia, so we can't compare the low voter turnout of the USA with Australia, but in general when voters go home empty-handed in larger numbers, then the voter turn out is lower. In reverse, a system that is more representative of all entices more folks to come out and vote.