It's not fool-proof. In Canada in 1952, the province of British Columbia switched to a ranked ballot and it nearly ended in disaster. The ranked ballot was an

It's not fool-proof. In Canada in 1952, the province of British Columbia switched to a ranked ballot and it nearly ended in disaster. The ranked ballot was an attempt by the traditional Liberal and Conservative parties to keep a rising socialist party from gaining power, as they assumed no Liberal or Conservative voter would choose the socialists as their second choice. But there was so much animosity between the parties that most voters chose a fringe right-wing party as their second choice, as a protest vote. The two traditional parties were wiped out and the fringe right-wing party narrowly won, despite having no leader and little governing experience. Fortunately, saner heads took over the fringe party and quickly steered it to the political center as a sort of big tent party for former Liberal and Conservative voters. But it could have gone very differently. The ranked ballot idea was quickly dropped, but the event shaped British Columbia politics for the next 60+ years. That fringe party elected by accident became the province's natural governing party. I suppose the moral of the story is that no voting system can prevent irrational voters from shooting themselves in the foot.