US election: How does the electoral college work?

The American president is not directly elected by US voters but by 538 electors representing the states. Voters go to the polls and in 48 of the 50 states, the candidate who gets the most votes wins all of that state’s electors (the two exceptions are Maine and Nebraska, which send electors on a more proportional basis). The number of electors reflects each state’s population, from Alaska’s three to California’s 54. To become president, a candidate needs at least 270 votes.
This means it is possible to lose the popular vote but win the election. In 2016, Hillary Clinton beat Donald Trump in the popular vote by 65,844,954 (48.2 per cent) to 62,979,879 (46.1 per cent). But Trump won the electoral college by 304 to 227. In 2000 Al Gore beat George W Bush by half a million votes but Bush won 271 to 266 when the supreme court awarded him the state of Florida.
It is generally deemed that Republicans enjoy an advantage in the electoral college, due to their strong support in smaller, more rural states, which tend to be slightly over-represented. In fact, over the last three decades Republicans have won the presidency three times but have won the popular vote only once (Bush in 2004). While there have been attempts over the years to reform the electoral college system, they have always failed.
Because most states employ a winner-takes-all system, there is little point for either party in spending time or money in a state where the result is a foregone conclusion. Nobody has any doubt that Kamala Harris will win Massachusetts or that Donald Trump will win Oklahoma. So the parties focus their attention on the handful of swing states that will actually determine the result. Which states are swing states can evolve over the years; Florida and Ohio were seen as swing states only a few years ago but are now pretty firmly Republican.
In the 2024 campaign, there are seven swing states, three in the “rust belt” of the upper midwest (Michigan, Pennsylvania and Wisconsin) and four in the “sun belt” of the south and southwest (Georgia, North Carolina, Arizona and Nevada). In 2020 Joe Biden won all of these with the exception of North Carolina, resulting in a comfortable electoral college victory of 306 to 232. At state level, however, some of the margins were agonisingly small. Biden won Arizona by 0.3 per cent and Georgia by 0.2 per cent. Despite Biden winning by seven million votes nationally, it has been calculated that if a little over 100,000 votes had gone the other way across the swing states, Trump would have won. The tightness of the margin was one of the motivations for Trump’s subsequent false claims that the election had been stolen, and for the efforts he made to pressure officials in states such as Georgia to “find” more votes for him – efforts that are the subject of an ongoing criminal prosecution.
They are generally local officials appointed to carry out what has historically been seen as a purely ceremonial task, confirming the results in a series of events culminating in the inauguration of the new president the following January. Four years ago, however, the process was more fraught, with Trump and his allies unsuccessfully mounting legal challenges across the country, seeking to replace some electors and arguing that the result should not be certified (as the constitution requires) by then vice-president Mike Pence. Those attempts culminated in the riot at the Capitol in Washington DC on January 6th, 2021, following which Joe Biden’s victory was approved by Congress.
In the highly unlikely but not impossible event of a 269-269 electoral college tie, under the 12th amendment to the constitution, the decision goes to the House of Representatives, which votes on a state-by-state basis (ie each state gets one vote, determined by its congressional representatives). So in this instance, California and Alaska have equal votes. If that were to happen, Donald Trump would almost certainly become president. Just to add a bit of extra spice, the Senate picks the vice-president. So, in theory, you could end up with a Trump-Walz administration.