Some critics try to attack preferential voting via the argument that it's too complicated. They say that it's too hard to explain how instant runoff voting or Condorcet's method work; and because of the complexity, voters will never like it.
I would ask these people to explain--in plain language and as few words as possible--how our current system work. But don't forget the primaries. Because the primaries are as decisive, if not more decisive, in determining our pressident and other elected officials, then anything that happens in early November. And if you read my state-by-state description in the comments of the first post, you'll notice that every state's primaries are also a little different.
Why do we even have primaries? Because the parties know that running multiple similar candidates is the best way to ensure that none of them win. This is identical to how a third-party candidate can pull support away from their most-similar major-party candidate and give the election away to the (mutually hated) opposition. The primaries exist solely as a way for the like-minded party members to agree to restrict the choices of the general electorate in order to avoid this vote-spliting effect, by compromising on a candidate which the whole group will agree to support. (Actually, you could argue that's the only reason political parties exist.) In other words, primaries and preferential voting try to solve the same problem. One through a complex, fractionalized labyrinth that actively prevents many voters from participating while giving disproportionate power to the leadership of the two major political parties, and the other by giving every voter a better (if slightly more complicated) way to express their choice. I think you can guess which option I would choose.
This may imply that, for instance, Hillary Clinton could have stayed in the race without increasing the chance that John McCain would have won, if we used a preferential system. Is that true? I would love to give you an unequivocal "yes", but I'll have to hedge a bit and say "almost certainly yes, but maybe not". For a full answer, we'll have to get into the nitty-gritty of voting systems and voting criteria; stay tuned! (I already made one assumption about criteria in this blog, on Friday. Can you find it?)