In addition to the simplicity issue, IRV can have a practical problem of legitimacy, when the elected official is everyone's 10th choice (I exaggerate for effect).
There are some arguments for allowing that, but I think the argument against is stronger - officials need legitimacy to serve effectively, otherwise we have a period of political instability which will end badly, and 10th choices won't practically have legitimacy. In Approval voting the preference order is a bit hidden so this doesn't happen. One of those cases where treating an election as if it's not an opinion poll at all is the better choice.
If the preferences have run off to 10th place; the first 9 choices are controversial enough they wouldn't have legitimacy either.
Look at America - the president has so gained so much legitimacy from FPTP that the House is trying to eject him from office. Voting system doesn't help with that much.
That is an argument like the Chinese claiming democracy wouldn't work because China is different. In theory it can't be instantly debunked, but in practice it seems to be a non-issue (compared to alternatives) when IRV is tried.
What's happening in America is not due to the election result, not anymore. That has more to do with the President's... temperament, and some very particular circumstances.
If it was just FPTP where he won more electors but less votes, he would have been seen as legitimate by now, just like Bush was.
I disagree. Polling in 2016 clearly showed Trump and Clinton were each individually the two least-liked nominees in their parties in modern presidential history. First-past-the-post and bitter primaries were largely responsible for the result-- over a third of voters remained at home on Election Day 2016. In some electoral systems, they even have an option to reject all nominees in these kinds of situations.
I thought about the general elections. As for the primaries:
* Clinton locked out nearly all of the viable opponents by using institutional control, the only one left was one sufficiently outside the Democratic party so she had a strong institutional advantage. No voting system could have fixed that.
* Trump actually had some popularity as a second choice among Republican primary voters, and we see that later on when only Cruz and Kasich were left. The other candidates' failure were more mundane - Not taking Trump seriously, op research failure, Trump being able to coordinate with Christi while the others were less able to coordinate, etc.
* The option to reject all nominees.. is interesting, but can lead to a 2nd/3rd ballot while the government is semi-paralyzed. It may not be a good idea to allow that.
> Clinton locked out nearly all of the viable opponents by using institutional control, the only one left was one sufficiently outside the Democratic party so she had a strong institutional advantage. No voting system could have fixed that.
Uh, yeah, simply not having voting superdelegates in the nominating contest (a reform to the candidate-selection voting system Democrats made in response to 2016) would have likely fixed (or at least mitigated) that, since the nominating contest was close even with the early superdelegate commitments and the effect that had on the perception of inevitability.
A general election direct (no electoral college) voting system like Bucklin or IRV, modified some that the same ballots, skipping votes for the winner, were tallied again by the same method to select the vice president, encouraging a party to bring it's two independently strongest candidates into the general election (and increasing the space for other parties or independent candidates) would absolutely both discourage that and limit the effect it would have on constraining viable general election choices.
(The same system internally to the party for choosing the Presidential and Vice Presidential nominees also would fix it.)
The superdelegates went for Clinton because there wasn't any serious institutional D challenger (Sanders was an independent before), so Clinton had by default a huge advantage there. If there was a serious internal D challenger, the picture would have been far more equal.
IRV can make the contest more fair than the previous voting system, but it can't make candidates run...
> The superdelegates went for Clinton because there wasn't any serious institutional D challenger
No, that's s almost exactly backwards. A key way Clinton locked out other traditional candidates was to secure an unusually large number of superdelegate commitments extremely early, needle other candidates would normally commit to the race.
> IRV can make the contest more fair than the previous voting system, but it can't make candidates run...
Yes, it can. Running in a Presidential primary (and the same is true of many other races) is an investment of time and resources people make—or avoid—in part because of the perceived prospects for success factors like a competitor having a substantial share of the total available vote sewed up before you decide, or a voting system that naturally narrows the field people will actively consider during the campaign do, very much, effect who decides to run.
Literally the point of IRV, Approval Voting and so forth is allowing viable 3rd parties not endorsed by the official channels of the major parties. They fix precisely this sort of problem. Democrats could have voted for a different left-leaning candidate without advantaging the right wing of politics.
There wasn't a coordination issue between 100 small left-leaning candidates for the Clinton opponents to choose - in that scenario IRV/AV would have helped. In the real scenario, the problem was solved for them by having only 1 option...
The candidate who is everyone's 10th choice can't win. To make it through the first exclusion the candidate has to be more people's first choice than at least one other candidate.
The legitimacy argument of IRV is that the winning candidate needed to accrue 50%+1 of first-and-subsequent choice votes, so they are at least the preferred winner over the second-place candidate by a majority of the electorate.
I did exaggerate (and said I did), but my point was that IRV makes it very obvious when a candidate loses badly on 1st order preferences but wins based on subsequent choices.
That can be argued as an IRV benefit over other systems (the winner knows s/he's on thin ice! The winner does have 50%+1 overall!), but the other way to see it is that the winner would be hobbled and would have difficulty governing effectively, and a voting system that emphasizes the ranking a bit less might have had the same result but with the winner having more legitimacy following the election.
There are some arguments for allowing that, but I think the argument against is stronger - officials need legitimacy to serve effectively, otherwise we have a period of political instability which will end badly, and 10th choices won't practically have legitimacy. In Approval voting the preference order is a bit hidden so this doesn't happen. One of those cases where treating an election as if it's not an opinion poll at all is the better choice.