By Bo Erickson

WASHINGTON (Reuters) – Seven battleground states — Arizona, Georgia, Michigan, Nevada, North Carolina, Pennsylvania and Wisconsin — are expected to play a decisive role in Tuesday’s U.S. presidential election between Democrat Kamala Harris or Republican Donald Trump.

Here are ten counties to watch in those states. Early results based on partial returns may not be predictive of the final vote tallies in the counties.

MARICOPA COUNTY, ARIZONA

Home to Phoenix, Maricopa County, Arizona, is key to winning the southwestern state as it makes up about 60% of the statewide vote. In the 2020 election, President Biden won this county by 2.2 percentage points while former President Donald Trump won the county by almost 3 percentage points in 2016.

COBB COUNTY, GEORGIA

Large and racially diverse Cobb County in Atlanta’s northern suburbs is a spot Democrats could pick up the large number of votes needed to win the state, as Democratic President Joe Biden did in 2020 when he won the county by about 14 percentage points. In 2016, Democratic candidate Hillary Clinton carried Cobb county by just 2 percentage points and lost the state to Trump.

BALDWIN COUNTY, GEORGIA

In central Georgia, Baldwin County is much smaller than Cobb but an indicator of Black voter turnout, as about 40% of voters in this county are Black. This is one place in Georgia where Biden’s 2020 margin was narrower than Clinton’s in 2016.

WAYNE COUNTY, MICHIGAN

Home to Detroit’s 1.7 million residents, Wayne County, Michigan, is about 40% Black. Biden in 2020 won this county with more than 68% of the vote, helping him clinch the state.

WASHOE COUNTY, NEVADA

In the northwest corner of Nevada around Reno, Washoe County is less racially diverse than the Las Vegas area, but has been trending more Democratic in recent elections. Biden won this county by more than 4 percentage points in 2020 over Trump.

WAKE COUNTY, NORTH CAROLINA

The city of Raleigh in Wake County, North Carolina, has boosted statewide turnout for Democrats in recent elections, as was the case when Biden in 2020 won 65% of the vote in the area. That was not enough to keep Trump from carrying the state in 2020.

ERIE COUNTY, PENNSYLVANIA

Erie County in northwest Pennsylvania has voted for the winning presidential candidate in the last four elections, including Biden in 2020 when he won the county by 1 percentage point. In 2016, Trump won this county by 2 percentage points.

BUCKS COUNTY, PENNSYLVANIA

North of Philadelphia, Bucks County, Pennsylvania, is another highly competitive county due to its large population of working class voters — a demographic group where Trump has made major inroads in his eight years on the national political stage. Trump is looking to win back the state — as he did in 2016 — but Biden won this county in 2020 by 4 percentage points, which helped him clinch the state.

CUMBERLAND COUNTY, PENNSYLVANIA

The suburbs of Harrisburg, Pennsylvania’s capital, have supported Trump in the last two elections. But Democrats could cut those gains in Cumberland County by attracting the area’s growing population of white collar workers. In 2020, Trump won this county by 11 percentage points.

WAUKESHA COUNTY, WISCONSIN

The populous western suburbs of Milwaukee, Wisconsin, have been another stronghold for Trump in his past two campaigns and the Republican won Waukesha County by more than 20 percentage points each time. Voters here will need to vote for Trump again at similar levels in order for Republicans to win back the state that Biden carried in 2020.

(Reporting by Bo Erickson; Editing by Scott Malone and Deepa Babington)