US election 2024: What is the Electoral College and why is it important?
Words by Angus Neale, ITV News Assistant Producer
When Americans vote for their president on November 5, they will technically not be voting for Kamala Harris or Donald Trump.
Instead, they will be electing members of the Electoral College – known as electors - who choose the president and vice president.
The system, which has been used for more than 200 years, was created by the Founding Fathers as part of the Constitution.
According to the US National Archives, it was established, in part, as a compromise between the election of the president by a vote in Congress and the election of the president by a popular vote of qualified citizens.
So, how does it work?
Each of the 50 states is allocated a different number of electoral votes based on the size of the population, with three being the minimum number a state can be allocated. These votes refer to ballots cast by electors on behalf of the state.
California is the most populous state with around 39 million residents and has 54 electoral votes. The least populated state Wyoming, with fewer than 600,000 people, has three electoral votes.
The majority of states use a winner-takes-all model – like the UK's first-past-the-post system. The candidate that gets the majority of votes in that state wins all its electoral votes.
Maine and Nebraska work differently, allocating two votes for the state winner, and then one for each congressional district. This split vote rarely matters, but in an election this close it could make the difference.
There are a total of 538 votes in the Electoral College, so a candidate must win a combination of states that takes them up to the magic number of 270 to take the presidency.
Why does it matter?
In 2020, President Biden won 306 electoral votes, 36 votes clear of 270. Biden’s three narrowest victories: Georgia (by 11,779 votes), Arizona (by 10,457 votes) and Wisconsin (20,682 by votes) are worth a pivotal 37 votes.
That means the election was decided by only 42,938 votes even though Biden won the popular vote by more than seven million. Around 240 million Americans were eligible to vote with a final turnout of over 150 million. This means that 0.003% of voters effectively decided the outcome of the election.
On five occasions, including in two of the last six elections, candidates have won the Electoral College despite losing the nationwide popular vote. In 2016, Hilary Clinton secured almost three million more votes than Donald Trump.
It is also worth noting that electoral votes are redistributed after the census. This has worked to Trump's advantage as the states he won in 2020 have grown more than those won by Biden.
What are swing states?
Most states lean heavily towards one party and are generally considered safe states - so the focus is usually on a dozen or so swing states that can flip the election.
There are those in the 'rust belt': Pennsylvania, Michigan and Wisconsin - Midwest states that are the industrial heartlands of the US. There are also those in the 'sun belt' to the south: Arizona, Nevada, Georgia and North Carolina.
Biden won all of them apart from North Carolina in 2020, so Trump is going to have to turn a number of blue states red if he wants to return to the White House.
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These states are the focus of the campaigns, with AP analysis showing that three-quarters of the more than 200 presidential campaign stops have been to the battleground states. These have been concentrated in counties with 22.7 million registered voters, just 10% of all voters registered for this year’s presidential election.
How can Harris and Trump get over the line?
The race for 270 votes can be imagined like building blocks in a tower.
Starting with the foundations - the safe and likely seats which each candidate expects they will win - Kamala Harris would be on 226 and Trump 219. We're putting Florida in Trump's column for now as he's likely to win there.
The most obvious path for Harris is the so-called Blue Wall in the 'rust belt'.
Trump could win Nevada, Arizona, Georgia and North Carolina, but if Harris wins Wisconsin, Michigan and Pennsylvania - barring any shocks elsewhere on the map - then she'll hit 270 and become president.
But in that scenario, Trump just needs to flip one of those states to win. And the polls say they are all incredibly tight.
So if Pennsylvania backs Trump, as it did in 2016, he's over the line with 287 and Harris is left on 251 - 19 short of victory.
Harris would have to do what Biden did in 2020 and hold on to Georgia - no small feat - or become only the second Democratic candidate since 1976 to win North Carolina. Both are worth 16 Electoral College votes and would get her over the line.
But then there is a possibility that Trump wins in Michigan.
There are a lot of Arab American and Muslim voters there who are frustrated about the US response to events in Gaza.
In this scenario, if Michigan goes red, the college will be tied. Harris and Trump locked on 269, one short of victory.
Trump’s most direct path to victory would be securing Pennsylvania and Georgia and maintaining his victories elsewhere. However, after Hurricane Helene, this strategy may become a greater challenge.
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