There are lots of baffling things about the US guns, writing the date the wrong way round, and the continued use of imperial measurements.

But one of the most confounding and consequential is how Donald Trump became president in 2016 despite losing the popular vote by a margin of nearly three million.

Its all down to the way in which the US elects its leader which centres on something called the Electoral College, and if you want to fully understand whats happening in the 2020 election , then this is the article for you.

What is the Electoral College?

Lets start with one very important fact that often gets overlooked the US president is not elected directly by citizens.

The way to think about it is its the states that elect the president, Christopher Anderson, professor of politics and policy at the London School of Economics, tells HuffPost UK.

Really what were talking about is 50 separate elections, its not just one national election.

This might sound odd seeing as on election day millions of US citizens make their way to voting booths and cast their ballot for who they want to be president, but what theyre actually voting for is something called an elector.

There are 538 electors divvied up among all the US states and together they form the Electoral College. It is this small group of people that carries out the will of the public and actually votes for the president.

And in a further twist you may not be aware of, this doesnt actually happen until December, and theres very little to stop these electors going rogue and ignoring the public vote.

This sounds like madness and thats because it is, yet somehow the system more or less works.

Why does America use this system?

Its all about history of course. Oh, and a historical disdain for the average person on the street.

The first few years after the founding of the United States in 1776 were marked with much discussion of how to fairly elect a president in a country composed of independent states.

This was made even harder before the days of mass communication as a potential candidate would find it hard to get their message heard by all people across the country as would be required for a fair and informed popular vote.

The original idea was the people couldnt be trusted necessarily to make the right choice, says Prof Anderson. And they wanted to find a way of giving each state a voice in selecting the president.

The Founding Fathers instead envisaged a system of nominated electors who would be voted for by the public in each state.

These electors could then dedicate time to learning about the candidates and their policies and were then entrusted by the public to vote for the right one on their behalf.

Or, as eloquently and more than a little patronisingly put by Founding Father Alexander Hamilton :

A small number of persons, selected by their fellow-citizens from the general mass, will be most likely to possess the information and discernment requisite to such complicated [tasks].

And thus the Electoral College was born.

How has the Electoral College changed?

In lots of ways but the most important is that the general population of the US is now considered informed enough to responsibly elect a suitable president () without the need for electors to do it on their behalf.

In modern elections, the popular vote at a state level is still technically a vote for the electors, but these electors are expected to convey the will of that vote.

The total number of electors is equal to the number of representatives there are in the US Congress which is 535, 435 seats House of Representatives and 100 in the Senate.

The extra three electors are assigned to Washington DC as its where the president will live so is deemed quite important.