What are the swing states in the 2024 US election and why are they important?

The National examines the significance of the battleground states and why both Donald Trump and Kamala Harris are spending so much time campaigning there

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As Election Day approaches, all eyes are on a group of US states that could help decide whether Kamala Harris or Donald Trump takes the Oval Office.

Ms Harris and Mr Trump have focused most of their energy in recent weeks on campaigning in Pennsylvania, Michigan and other swing states in an effort to secure victory.

Here, The National examines the significance of the swing states and why both candidates are spending so much time campaigning there.

What is a swing state?

Swing states, also known as battleground states, are those that could "swing" to the Democrats or Republicans in an election. They have often been won narrowly by one candidate or the other in previous presidential elections.

The US uses the Electoral College system, in which state-appointed electors cast votes for one of the candidates, with 270 votes needed to win.

With a certain number of "safe" states voting reliably Democrat or Republican in each election cycle, swing states play a major role in the outcome of the election.

What are the current swing states?

• Nevada (6 electoral votes): While it might not have many electoral votes, a win in Nevada could help either Ms Harris or Mr Trump clinch the election. The state has gone to the Democrats for the past four presidential election cycles but previously, it was staunchly Republican. Since 1900, the Nevada presidential winner has won the White House in nearly 90 per cent of elections, according to Ballotpedia. Ms Harris has a 0.6-point edge in Nevada, according to FiveThirtyEight, while a recent Emerson poll found she was leading by one point, 48 per cent to 47 per cent.
• Arizona (11 electoral votes): Joe Biden was the first Democrat to win Arizona since 1996 and the state is once again the focus of a great deal of speculation. About one in four voters in Arizona is Latino, a group that has traditionally leaned Democrat, but that could change amid rising concern over the border and the economy. Phoenix, the state's largest city, and its suburbs were previously staunchly Republican but there are growing pockets of Democratic support, according to the Brookings Institution. Current polls appear to give Mr Trump a narrow edge over Ms Harris but Mr Biden took the state by only 0.3 per cent of the vote in 2020.
• Michigan (15 electoral votes): The state has voted Democrat in every presidential election since 1992, but Michigan is seen as a toss-up this cycle. The state has presented a sizeable challenge for Democrats due to its significant Arab and Muslim-American communities and their anger with Ms Harris and the Biden administration over US support for Israel amid the Gaza war. The "uncommitted" voter movement, headed by Arab-American community leaders, has refused to endorse Ms Harris while warning supporters away from voting for Mr Trump or a third-party candidate. A recent Quinnipiac poll showed that Ms Harris has an edge over Mr Trump in the state, but it is unknown if this will hold up on November 5.
• Wisconsin (10 electoral votes): The quintessential "purple state" has gone to the Democrats over the past several presidential elections. It went to Mr Biden in 2020, but Mr Trump was able to flip it red in 2016. Part of the Rust Belt, Wisconsin's working-class voters are a key bloc. The state's mix of cities, small towns and vast rural areas has made it one of the most contested of this election cycle. Republicans held their national convention in Milwaukee over the summer and Ms Harris held her first rally in the state in July. The latest collection of polling from The New York Times shows Ms Harris and Mr Trump are in a dead heat in Wisconsin.
• Pennsylvania (19 electoral votes): Both Mr Trump and Ms Harris, as well as their running mates, have spent a large amount of time campaigning in the state, which has a hefty number of electoral votes. It is the place where Mr Trump was the target of an assassination attempt this year. Mr Biden won the state by 82,000 votes in 2020. The state is a mix of urban and rural areas, with a diverse population. According to calculations by elections analyst Nate Silver, the candidate who wins Pennsylvania has a more than 90 per cent chance of winning the White House.
• North Carolina (16 electoral votes): Though North Carolina has voted for the Republican candidate in almost every presidential election over the past several decades, observers highlight the small margins of victory in recent contests. The state also elected a Democratic governor in 2017, after Mr Trump took the state in 2016. According to a recent Quinnipiac poll, Ms Harris leads Mr Trump by two points in the state, while FiveThirtyEight and The Wall Street Journal give the advantage to Mr Trump – but not by much. The state is still reeling from the effects of Hurricane Helene, which killed almost 100 people and destroyed much of the blue-leaning city of Asheville this month.
• Georgia (16 electoral votes): Mr Biden flipped the traditionally Republican state in 2020 but whether Ms Harris will be able to bring another Democrat victory remains to be seen. Ms Harris has been campaigning hard in Georgia, launching a bus tour focused on reproductive rights this year. Early voting has already begun in the state and has already broken records in the area. FiveThirtyEight has Mr Trump leading Ms Harris by a narrow margin. Even though Mr Trump holds a slight edge, his standing against Ms Harris is significantly closer than it was against Mr Biden, before he stepped aside in July.