Every four years we interested observers from outside the USA become experts in the Electoral College and the predicted voting patterns of individual states. (In the run up to 2016 I used the primaries and campaign as a spur to increase my terribly feeble knowledge of the US states geography – Arkansas, yes I knew it existed, but where exactly?) We soak up received wisdom such as: that Virginia is blue now, but used to be red. Texas seems to becoming more purple. New Hampshire could be the only New England state to vote red. 

And of course we all get to discover that only some states are really worth following – it is unlikely after all that a GOP candidate will win Oregon, or that  a Bernie Sanders would take out Alabama. So we get focussed on the swing states, the bellweathers, those that are “up for grabs”. And then we focus on those swing states that are the most important, those with the highest number of Electoral College votes: perhaps Florida, or Pennsylvania.

The number of Electoral College votes that a state gets is equal to its representatives in the Congress (two per state for its senators and then a number equal to its members in the House of Representatives). In turn, the House of Representatives’ 435 seats are allocated to each state according to its share of the US population. Which is why a states’ population is important: it determines how many House representatives’ districts it is allocated and also how many Electoral College votes it has.

The USA conducts a census every 10 years, it is from this census data that the electoral allocations are made. The last census was held there in 2010, and thus the 2012, 2016 and 2020 elections will be held according to the Electoral College allocations arising from that data. This means that the Electoral College allocations for 2020 will remain the same as they were in 2016. California will retain the largest number of Electoral College votes by far (at 55) while Texas will come in second at 38.

However, the 2024 presidential election will see a different allocation of votes based upon the 2020 census. While of course we do not know what those final numbers will be, some pundits are starting to make educated guesses. It seems as if Texas and Florida will probably gain four and two votes respectively (four other states will also gain one extra vote each) at the expense of ten states which will lose one vote each, including Illinois and New York. This will reflect the growing population density of the west and south of the country. (Placing these predictions onto the 2016 outcome, Trump would have gained four extra votes while Clinton would have lost four.)

Further into the future, the middle decades of the twenty first century could see California cease to be the biggest political prize in Presidential elections, ceding that place to Texas. If the current growth trends in Texas and California continue, then Texas will be the biggest state in the Union by about 2045. Texas would sit at about 54 million people at the middle of the century, while California will hover at around 50 million. Between them, these two states will be home to a quarter of the population of the USA.

Furthermore, the Californian population is tending older as younger families are driven out of the state due to the high cost of living and ageing infrastructure. While international immigration is keeping the state’s current population afloat (indeed the Golden State's population is still increasing by 0.8 per cent a year) internally California is losing more people to other states than it is gaining in return.

Thus, if current trends continue, it seems as if the demographic dominance of the North East and California will continue to decline in the years ahead to the south-west of the country. And of course, this demographic shift will be reflected in the Electoral College map.