> ran into the establishment What he ran into was the inevitable math of a first past the post electoral system. You want third parties, you need ranked choice voting or something similar. Even if you're fine with the main parties, RCV is probably better in terms of electing who most people want. You could argue that Bush senior might have won with it if the Perot voters ranked 1) Perot 2) Bush. Bush junior might hav…
It makes it safe for you to give your first choice to a third party candidate who has no chance of winning, because they’ll have no effect on the result after being eliminated in the first round. But as soon as your third party candidate becomes a serious challenger, you’ll risk instead eliminating your second choice, whose redistributed votes are much more likely to favor your last choice.
https://www.electionscience.org/library/the-spoiler-effect/
So IRV is great for stopping weak third parties from upsetting the balance of the two-party duopoly, but not so great for helping strong third parties get a real chance at winning. If you want real change, there are much better systems available: take a look at approval voting, score voting, or Condorcet voting.