A short preamble for the reason of the question:
During the existence of the German Democratic Republic the population had not only the right to vote, they had the obligation to vote - a composed list of candidates. The approval of the list was very easy, you only needed to throw in an unmarked vote. The citizens were proud to show their decision so they demonstratively ignored the polling booths. It should be said that usage of the polling booths was completely voluntarily, there were absolutely no repercussions to expect during the election. To show disapproval, you only needed to add your concerns to the vote which were duly noted.
So even during the protests 1989, one year before the end of the GDR, the leading party claimed 98,85 % "yes" votes with a voter turnout of 98,78 %. Those people saying that they checked the votes and found massive discrepancies, well, don't you trust the leading party ?!
It seems that.."authoritative regimes" have a massive problem with their self image that they put out those ridiculous numbers. My experience is that if in a multi-party system a party gets over 50%, it's champagner time and if they would get over 66%, the party leaders would sell their soul and their grandmothers as give-away.
Which leads to the question:
To get a realistic picture what approval rates are possible for democratic votes with a great number of voters, what is the highest ever win achieved in a democratic decision ?
Elections are preferred, but I am interested in every important decision.
At least 20% of the population in a given area (state/country), at least 500 000 people.
- Fair (No tricks like gerrymandering allowed)
- Free (No obligation, no pressure to vote)
- Equal (Everyone has exactly one vote)
- Secret (The enthusiasm for a political goal still allowed the people to vote secretly and there were no repercussions against polling booths).
- Direct (The decision does not need intermediaries. This kills US presidential voting with electors).