Note: This is an oversimplified explanation of how the US President is elected. Overall, the procedure is quite intricate and can have various scenarios and conditions.
Imagine that you work in a 100-employee company (with 10 departments) that chooses its CEO through an election.
One option for the election is to have all the employees to vote.
Let us say there are 2 candidates, and whoever gets 51 votes becomes the CEO – this is how most democracies elect their heads of state.
The other option is to get each department’s employees to elect 1 out of 2 or more candidates from their department and then these 10 winning representatives (one from each department) vote for the election of the CEO.
So, the employees don’t get to vote for the election of the CEO, but for the election of department representatives.
The candidate who wins 6 of these department-representative votes becomes the CEO.
This 2nd method explains how the US elects its President, but instead of 10 department representatives, it has 538 electors.
These 538 electors (each belonging to either democratic or republican party) put together are called the Electoral College.
Whomever 270 out of these 538 electors vote for, becomes the President of the United States.
The number 538 is based on the population of each state – roughly one elector per 700,000 people + 2 (if the population of a state is less than 700,000, it will have 1+2 = 3 electors).
For example, the population of California as per Census 2010 was 37.25 Million, and if we divide this number by 700,000, we get 53; add 2 to 53 and you get 55 and that is the number of electors California has.
Now, let us say Democrats (Biden), Republicans (Trump) and 3 smaller parties are contesting for these 55 elector votes, and the Democrats win 30 of these 55.
In this case, all 55 votes would go to Democrats; the others (Republicans and smaller parties) will get no vote – this is called the-winner-takes-it-all policy.
This policy makes the big states really powerful – a party winning a majority in just 4 (New York, Texas, Florida, and California) of the 50 states would have over 150 of the required 270 votes.
And it also explains why the US election may forever remain a 2-party election despite the existence of several small parties (even if small parties win an elector vote here and there, the winner will take their wins also).
While a majority of a party in the Electoral College, in effect, means that the Presidential candidate of that party would become the President, but there have been instances when a few electors of a party have voted for the opposition candidate because they didn’t like their own party’s candidate.
