The problem is that third partyers have no chance anywhere here in the states, so voting for them in the primaries and general elections are a waste of time and only turns the votes over to the rats
The ONLY way I see for 3rd parties to be relevant is to campaign on their issues, and then agree to endorse a major candidate in exchange for concessions on policy. It’s not the same impact as a minority party has in a parliamentary system, but it could result in them getting some of what they want instead of their throwing an election to those they absolutely disagree with.
Instant run-off elections would break the 2 party monopoly,
which is exactly why we won’t be seeing it.