Unsurprisingly, I'm not a big fan of the Gibbard–Satterthwaite theorem either. It does apply more broadly than Arrow's, but my understanding is that even thoug

Unsurprisingly, I'm not a big fan of the Gibbard–Satterthwaite theorem either. It does apply more broadly than Arrow's, but my understanding is that even though a tactic will exist for every voting system, that tactic may require perfect information or at least isn't guaranteed to be actually exploitable by any voters taking part. If a tactic is so complicated and likely to backfire that no one ever attempts it (or the people that try it, on average, end up harming their cause) then I think that the threat of tactical voting is insignificant. What I don't know, unfortunately, is which voting system is best in terms of ease of voting honestly and difficulty of voting tactically. Determining that may involve knowing things like how people respond to polling data, or to one party telling their followers to fill out their ballots in a certain way, which might be hard to model.