(Skip to conclusions) (Executive Summary)
Let me focus my discussion on the USA (which is where I live).
There are several possible approaches:
Of these alternatives, #1 seems out of reach and history suggests will remain out of reach until a large number of states have already adopted improved voting systems (that is what happened with allowing women to vote and with direct senatorial election in the US – the states moved first and only later did a US-wide constitutional amendment occur). I can only think of one way #1 could get moving – if one of us successfully runs for US president. A likely story.
#4 seems a waste of time: Cambridge MA has used STV voting for years and nobody noticed. There is no point to doing something nobody notices. Even NY City may be too small to have an impact (did you know NY City once employed a different voting system? Anybody know what and when? ...I thought not.)
So we must focus on #3 and primarily #2. (However we shall see the obstacles to #2 are large and will be reduced if #5 is done first.)
#2 has been tried before and reached the floor of some state legislatures, with, e.g. Steve Brams testifying before the NH state legislature. All such attempts have failed. I suggest to you that no legislature will willingly change the system that got them elected. That is why countless election reform attempts worldwide have failed. Britain's ERS has tried for over 100 years without success in Britain and they are a hell of a lot better organized and bigger than us, and operating in a smaller country.
That suggests the legislature probably has to be bypassed and we need to go directly to the people.
The following US states allow statutes to be passed by "initiative":
The usual procedure to run a voter initiative is: you formulate the wording very carefully of your initiative, then you collect signatures to get it put on the ballot. (See ballotprop for possible model wording.)
Maybe 50,000 signatures need to be collected (amounts may vary in your state; look it up). It is possible to collect about 100 signatures per day in malls, subway stations, etc.
As you can imagine (do the math) it will take a lot of volunteers, time, and money to collect enough signatures. To get the money we need somebody rich, or a grant from the likes of, e.g. George Soros, Ross Perot, Rockefeller Foundation, etc.
Enough volunteers are theoretically already available inside the Green party, Libertarian party, Constitution Party, etc. However, that requires the leadership in those parties to get enough of a damn clue to realize that
So far, I have seen no sign that third-party leaders recognize these facts, and all US 3rd parties seem to have a great interest in suicide. With enough money to run an advertising campaign it might be possible to change that. You could also try telling and talking and writing to party leaders. I have tried that with the Green party and it didn't work; but we did have some success with the Libertarian and Socialist-USA parties, both of whose 2004 presidential candidates now have endorsed CRV. Perhaps I am not persuasive since e.g. I do not have lots of money, am not well known to them etc. If it were George Soros talking, they'd listen.
Now, assuming we succeed in getting range voting on a state ballot initiative, then the initiative will fail. Polls conducted by me, Greene, and Quintal (paper #82) have shown that US voters, given a minute or so to think about it, prefer to keep plurality voting and not to switch to either approval voting or range voting. There are some indications (but the statistics are not convincing of this) that they prefer approval over range, but it is definitely clear they prefer plurality over either.
That means that just getting an initiative on the ballot will not be good enough. There also has to be a simultaneous massive media and PR campaign to educate the public on this. That requires very big bucks, we are talking 1 million dollars and maybe more per state targeted, and some intelligence about how to spend it. (And just the fact something is on the ballot does not imply it will get media attention. Tons of state ballot issues get almost zero media attention.)
If and when a lot of states adopt range voting, then the stage will be set for a nationwide attempt. This will all take about 10-20 years at a minimum.
Now since I imagine probably we are not going to be rolling in $millions soon, nice try but... the above approach probably is still not good enough, i.e. doomed to fail. Therefore we need to find a way to get free massive publicity and education. After everybody has been exposed to that, then we are in a better position to fire up the above strategy of ballot initiatives with 3rd party volunteers.
That is where Paul Kislanko's idea comes in. He writes: "I personally am not sold on AV [RV] for general elections. But I think it is absolutely perfect for party primary elections." Note: range voting's comparative advantages are greatest when the number of candidates are large, which often happens in primaries, and where there are no clear "frontrunners" – which also often happens.
"And that doesn't require constitutional amendments or anything else - parties get to choose whether to even hold a vote, witness the "caucus" states. Where the states pay for the primary elections, a party choosing to use approval might have to subsidize the non-plurality collection/counting process, but getting an advocate in front of a state party commission is a lot easier than getting elected president."
This thinking suggests we want to find a magical place where
But what is this magical place?
Two words: "Iowa Primary Caucuses."