In 16 days — on the 20th of January 2021 — Joe Biden will take office as the 46th president of the United States. As a result of November’s USA presidential election, he won with 51.4% of the general votes and 56.9% of the electoral votes. Such developments — winning by a hair — in presidential’s or Prime Minister’s elections are more and more often. Taiwan’s president, Tsai Ing-wen, was elected with 57%; Luis Arce became Bolivia’s president with 55.1%.
We rarely observe clear results, and when we do — Russia, Vladimir Puttin or North-Korea, Kim Jong-un — fraud is suspected. Some might say that this depaints more divided populations, a not-so-good thing when unity is needed to solve dozens of arising global problems. Of course, some countries still show unity: UK’s PM, Boris Johnson, won the last election with 78% of the votes.
Thus, crucial questions arise: is 51% enough? Can a country stay afloat when its population seems so divided? Finally, if such results aren’t enough, what other choice do we have? Should “unanimity” replace “majority”?
Why do we use the majority?
“A majority […] is the greater part, or more than half, of the total.” 
Therefore, simply speaking, the majority is more than 50%. For an election, half of the voters. Everyone knows that. Indeed, we all use this concept, starting from a very young age. From electing class rep to choosing in which restaurant to eat when you’re out with friends. But why?
Well, the answer isn’t very complicated. It is the simplest and fairest way. During debates, it is the easiest way to decide.
Kenneth O. May (1915–1977), an American mathematician, even demonstrated why “majority” was the best possible solution. May’s theorem  characterizes majority rule as the unique rule that satisfies anonymity, neutrality, and positive responsiveness with a finite number of voters.
Of course, suppose you live somewhere else than in the US. In that case, chances are the election process is different and might not require a majority but rather: a plurality.
The plurality rule
Plurality makes the option with the most votes the winner, regardless of whether the fifty percent threshold is passed. Canada or Germany use this system. Justin Trudeau, Canada’s PM, was re-elected in 2019 with 39.47% of the votes. The following opponent in the list, Andrew Scheer, received 31.89%.
In general, elections adopt the plurality rule when they oppose more than two contestants. (oops, don’t get me wrong, the US election, for example, engages more than two opponents, you got the Libertarian party, the green party… Still, only two parties got the monopoly, the Republicans and Democrats.)
So plurality means that you only need to have more people by your side — voters — than your opponents. And this can be even more problematic in our situation. Let’s say you’re a group of ten and wish to eat together in a restaurant tonight. Three want to eat Japanese food, one Indian, one Chinese, two French, two Spanish, and the last Italian. If you go with the plurality rules, you’ll end up eating at a Japanese restaurant. Three-person will be happy, but the seven others? We don’t know for sure, but Japanese foods weren’t their first choice; therefore, they could be unhappy. So seven out of ten people, the majority, might be disappointed.
Even though, Robert Goodin and Christian List proved that plurality also respect May’s theorem.
Does it matter?
OK. So, in the end, 51% percent is enough, and even more than enough — in the case of plurality. But ultimately, being elected with 51% percent means that nearly half of the voters wish for someone else to have your place. And in the case of plurality, we even proved, in the last paragraph, that you could get elected with the vast majority of people not having wished for it. But does it matter? Are we on the verge of multiple civil wars, or will it change nothing? Well. It doesn’t seem to.
Most of us remember the last US election of 2016, won by Donald Trump with 56.9% of the grand elector and 45.9% of the general vote and lost by Hilary Clinton with 43.1% and 48%, respectively. Wait. This situation seems even more problematic since H. Clinton lost with the plurality of the general vote. But ultimately, Trump presided the United States for the last four years, and no civil war happened — it doesn’t mean that everything was going smoothly.
Why? A way to look at it is that a president or PM, in a parliamentary republic, only has so much power. In parliamentary republics, they are usually, but not always, mostly ceremonial. In the end, law and impactful decisions are mostly — it differs in some cases — done by the assembly of senators, governors, parliamentarians. Term my varies from country to country, but Democracy isn’t Tyranny. Ultimately, choices are made by a group of people and not a sol leader. Of course, this is only true in a country with the right balance of power.
But if a president has won by a hair, wouldn’t the parliament be divided as well? Sure, but the balance should weigh correctly. In the worse case, politics would not move (alternating between the two parties with the near majority). This, at the exception of a Tyranny of the majority . The Tyranny of the majority (or tyranny of the masses) is an inherent weakness to majority rule in which the majority of an electorate pursues its objectives exclusively at the expense of those of the minority factions.
So, in the end, it doesn’t matter as long as you have a true democracy, with a correct balance of power between the government and the parliament.
Unanimity, a vast utopia
So, the majority and the plurality rules are the easiest and maybe only directions possible. But what if we want a better system?
We’d all wish for unanimity. It’s always better when everyone agrees on the same restaurant, the same rules, or the same candidates. But, we all know that it is a complicated, even nearly impossible goal to achieve. It doesn’t mean it is never used. But it seems only applicable to a small group of people.
The European Council has a set of subjets — EU Membership, EU finance, etc. — where only a unanimous vote is judged acceptable . The united state constitution required unanimous jury verdicts in state criminal trials . So unanimity is applicable but only with a small group of people. The European council has 27 members; a jury is composed of 12 peoples.
Unanimity is limited to the number of decision-makers.
It can also be regarded as non-democratic or feel suspicious since the essence of Democracy is debate, and there is no debate when everyone agrees. 
Not the best but the only solution
So, in the end, the majority — and plurality — rule isn’t the best solution but the only possible one. Plus, it satisfies anonymity, neutrality, and positive responsiveness. Unanimity is better in its term but only applicable when confronting a small number of decision-makers.
Of course, you are free to forge your own opinion on this subject. And I even encourage you to do so. Maybe the 75% rule is better; perhaps it is too complicated?
What’s your opinion? Can you think of any better solution?
Let’s end this with a quote from Gandi:
“The rule of majority does not mean that it should suppress the opinion of even an individual if it is sound. The opinion of an individual should have greater weight than the opinion of many, if that opinion is sound on merits. That is my view of real democracy.”