In a deeply divided nation, the election is a real contest between Democrat Kamala Harris and Republican Donald Trump, meaning the outcome of the 2024 election will depend heavily on several key battleground states.

This means that the results also depend on several counties.

From 2012 to 2016, more than 200 counties flipped from former President Barack Obama to Trump. According to NPR, less than half of that number changed hands from Trump to President Biden in 2020.

Here are the counties to watch in each of the seven swing states as Election Day approaches.

Arizona

Maricopa County, Arizona, has emerged as the country’s ultimate swing county – a place that could determine whether Democrat Kamala Harris or Republican Donald Trump becomes the next president and which party controls the U.S. Senate.

The county, which is home to Phoenix and dozens of other communities, is so divided politically that it may take more than a week to know who won. This year, election officials warn it could take up to 13 days to record all ballots in Maricopa.

Pima County, which includes Arizona’s second largest city of Tucson, is considered another important county to keep an eye on. The traditionally Democratic district could give Harris more votes in the 2024 election.

Georgia

The 20 counties with the highest share of total active voter turnout were all won by Trump in 2020, even though Biden won the state overall.

The bluer counties in the Atlanta area are still significantly larger than the rural counties where voter turnout is high — but in a race that saw fewer than 12,000 votes in 2020, every ballot cast is crucial.

The three counties with the highest voter turnout are Towns, Oconee and Dawson – which were won by Trump in 2020.

In contrast, in Henry, Cobb and Fulton counties – the third being the city of Atlanta itself – fewer of the total active voting population voted before Election Day, but more ballots have been cast so far.

Michigan

Some of the top counties to watch in Michigan include Wayne County (home to Detroit) and Kent County (home to Grand Rapids).

Kent County, located in the western part of the state, could signal which direction Michigan is headed.

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It was once a Republican stronghold but has become increasingly Democratic in recent years. It was one of only three counties statewide to flip from Trump in 2016 to Biden in 2020.

Suburbs in the Detroit metropolitan area will also be important. Saginaw County flipped from Obama in 2012 to Trump in 2016 and then to Biden in 2020.

Nevada

Politicians in Washoe County, Nevada, call the county “the most vibrant county.” The county, which includes Reno, is the second most populous county in the state.

In 2020, Biden won Washoe by 4.5 points. According to political data expert David Wasserman, Democratic votes in that county could offset losses in Clark County, which includes Las Vegas, where the GOP has made gains in recent years.

North Carolina

In North Carolina, Harris’ margins in Wake and Mecklenburg counties, home to the state capital Raleigh and the state’s largest city, Charlotte, respectively, will show how much Trump needs to gain traction from the less populated rural areas he has dominated , according to the Associated Press.

Voters make their choice at their voting booths at an early voting location on October 17, 2024 in Hendersonville, North Carolina. (Image credit: Melissa Sue Gerrits/Getty Images)

Cabarrus County, in suburban Charlotte, has also been in the red in the last two elections, although Trump’s lead shrank from 20 points in 2016 to nine in 2020.

Meanwhile, Nash County near Raleigh flipped from Trump in 2016 to Biden in 2020, but won by a razor-thin margin.

Pennsylvania

In Pennsylvania, Harris needs high turnout in deep-blue Philadelphia, but she also wants to expand Democrats’ lead in suburban districts to the north and west of the city.

She campaigned aggressively in Bucks, Chester, Delaware and Montgomery counties, where Biden surpassed Clinton’s 2016 margin of victory. The Philadelphia metropolitan area, including the four collar counties, accounts for 43 percent of Pennsylvania’s vote.

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Significantly, Northampton County has crowned the winner of presidential elections nearly three times since 1920, and the area is a battleground again this year, according to the Post-Gazette. As in Erie County, voters switched from Barack Obama to Trump to Joe Biden.

Wisconsin

Harris and Trump held separate rallies within seven miles of each other in Milwaukee, Wisconsin on Friday evening in a final election campaign in the swing state’s largest city.

According to local reports, four counties will decide who could win the swing state: Dane, Door, Milwaukee and Waukesha.

Biden won 181,000 more votes than Trump in Dane County in 2020, and Milwaukee County had a 183,000-vote lead for Biden.

Meanwhile, Trump received 55,000 additional votes over Biden in Waukesha County. Door County was red in 2016 and turned blue in 2020.