Does the 3rd party make sense in the US election system? My impression was that 3rd parties are unhelpful, since they steal voters from ideologically similar parties, thus helping the opposition.
> Ranked-choice voting is used for state primary, congressional, and presidential elections in Alaska and Maine and for local elections in more than 20 US cities including Cambridge, Massachusetts; San Francisco, California; Oakland, California; Berkeley, California; San Leandro, California; Takoma Park, Maryland; St. Paul, Minnesota; Minneapolis, Minnesota; Santa Fe, New Mexico; Portland, Maine; Las Cruces, New Mexico; and St. Louis Park, Minnesota.[1] New York City is the largest voting population in the US using RCV.[2]
I don't want to seem too optimistic but the US seems overdue for a more European style politics so if a big shift happened you could still end up with two parties, broadly left and right and Democrats (that remain) could be either of them.
In other places where FPTP results in more than two parties, this is usually because they run at lower levels first, to set the expectation that they can run something. it is also usually less costly to run in such races as the required outreach networks are smaller and media campaigns less expensive.
And US election campaigns at the national level are very expensive because it takes a lot of funding to do outreach to 330 million people over 9M sq km, plus media advertising slots are very pricey. Bernie Sanders spent $220M on his 2016 campaign, and that was for the primary. To put that in perspective, the maximum a UK political party was allowed to spend on all seats in Parliament was 19.5M GBP in 2019; the maximum spend on any single seat is 30,000 GBP.