third parties in the US are historically not very successful, but mostly because they tend to shoot for broke by running for President and failing. In other pl

third parties in the US are historically not very successful, but mostly because they tend to shoot for broke by running for President and failing. 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.