Comment by AnthonyMouse

> It's very unlikely that the two candidates I hate are on opposite extremes and both popular.

It's easy to hate the candidate on the opposite extreme from the way you lean, so all this really requires is for the extremist on your side to be a corrupt populist who gets support by telling people the lies they want to hear or is paying off the right people to get favorable media coverage or valuable endorsements. Or is just more extreme than you can accept but you're in a district with some people who want that.

Notice also that neither of these candidates are the first choice of the majority. They just have enough support in a >2 candidate race to not be the first knocked out.

> Ones where I don't feel the need to balance risk versus reward for candidates I moderately dislike.

This is Arrow's Impossibility Theorem again. All of them do that, because in the rock-paper-scissors triangle where no candidate can beat both of the others, you then need something equivalent to a score to choose the winner. At which point degrading your second choice hurts them against both your first and third choice and whether or not you should do that is influenced by how likely you regard it that other voters will favor your first choice over your third but not your second.

It's also a dangerous game because the error bars on polls are huge and it's more often than not that the final results are very different than anybody's wild guess from the day before they started counting the votes.

> If I'm moderately confident then I'm likely to do it despite the risk.

Suppose your true ratings would be 10 for your most preferred candidate, 7 for the second best and 1 for the inhuman monster the opposing tribe somehow supports for no explicable reason. Polls say your first choice is expected to score ~5, your second choice ~6 and your vile enemy ~4, but all of these are plus or minus 2 points or more because polls are practically random number generators. What are you going to do?

You have the option to try to tank your second choice to give your first choice a better chance, but it's still a very real possibility that your first choice ends up at 4 and the hated enemy at 5.

> The whole framing of the problem was that one of the candidates in the minority party wins. If there are four unrelated candidates that problem goes away. The more popular moderate won, not a big deal.

It's still the same, and the minority party candidate isn't necessarily that much of a moderate, they're just not a far extremist.

Suppose it's California and a Republican, a Democrat and a member of the Green Party are in the race. The district is 40% Republican and under the old system correspondingly 60% Democrat, but in a system with more than two viable parties, it's 40% Republican, 29.9% Democrat and 30.1% Green.

If you hold that election with RCV and the Democrat gets knocked out first, the moderate Democrats (which, with the Green candidate in the race, was all of them) have to choose between a California Republican and a Green Party candidate who proudly wants to raise the gas tax to $8/gallon and pull out of NATO. More than a third of the moderate Democrats choose the Republican over that and under RCV that becomes a Republican seat.

The same race with score voting only does that if people vote the way you seem to think they would, which is exactly their incentive not to.