Some argue that referendums - votes by the entire electorate on a single issue - should require more than a 50% majority to pass. This can ensure protection against extreme opinions, greater public agreement and counteract lower turnout, especially when it comes to voting on quintessential political issues.

Protection against extremes: Supermajorities can safeguard against extreme outcomes. A proposal that 66% of voters support will likely be more moderate than one passed by a slim 51%. Switzerland uses a double majority system for referendums. A majority of regional districts must vote yes and a majority of voters nationally. Such a system aids a country with regional and linguistic differences, generating public consensus and kicking back any extremes.

More agreement: Having a supermajority decide allows for more public consensus and less fighting around close results. Referendums often involve controversial matters where public opinion is evenly split. The Brexit referendum was won on just 51.9% of the vote, leading to years of division, with many calling for a second referendum.

Supermajority referendums can be a safeguard against more extreme views

Counteracts low turnout: Supermajority referendums set a higher threshold of voter support for a decision to pass, helping to offset the effects of low turnout in simple majority referendums. This reduces the risk of highly engaged extreme minorities pushing through decisions with limited public backing. The 1979 Scottish Independence referendum had a clause requiring 40% of the total electorate to vote “yes” for it to pass. While 52% of votes cast were for independence, this only came to 32% of all the eligible voters, so the pro-independence campaign lost.

Supermajorities cause different issues. The higher threshold breaks traditional democratic rules, results in gridlock and often has unspecified thresholds. 

Breaking Democratic Norms: Historically and in most democracies today, decisions typically reflect the majority's will determined by the 50% threshold. Requiring 60% of the French Congress for constitutional changes in the French Republic can feel counterintuitive compared to the traditional perception of democracy for most citizens, and the electoral rules being 50%.

Gridlock: A supermajority can slow progress in providing effective answers to key issues. Amendments to the US Constitution require a two-thirds vote in favour by members of Congress. This rule is also tricky, given a narrow two-way split between Democrats and Republicans. That’s why just 27 of 11,000 proposed amendments have been ratified. While this condition ensures some stability, it makes it extremely difficult to pass significant reforms.

What is an appropriate threshold if not 50%

Difficulty in choosing a threshold: What is an appropriate threshold if not 50%? No definite answers have been made yet. Scotland’s referendum mentioned above was controversial because of the arbitrary requirement for 40% of the electorate to be in favour. The 55% boundary in the 2006 Montenegrin independence referendum was narrowly met, but the process of agreeing on this threshold was complicated and messy.