These are the counties to watch on Election Day

All eyes are turning to seven critical battleground states Tuesday that will determine whether former President Trump or Vice President Harris takes the White House.

Within those states, different counties can offer us early clues of how both parties are faring, including how well Republicans and Democrats are energizing their bases.

Here’s a list of some of the key counties to watch for on election night.

The Atlanta metro counties

Georgia is the first of the seven swing states to close its polls. The state went for Trump in 2016 by 5 percentage points, but President Biden won it in 2020 by roughly a quarter of a percentage point.

One dynamic to watch for, which NBC News national political correspondent Steve Kornacki noted in a recent podcast, is how well Democrats expanded their gains in the Atlanta metro counties — which he dubbed the “blue blob” — and whether Republicans will be able to curb some of its backsliding in the GOP-leaning Cherokee and Forsyth counties.

“Is the blob expanding?” Kornacki asked on “Pod Save America” on Sunday.

“There's one county in that area, it's been moving pretty dramatically towards Democrats, but just missed — Fayette County — the last time around,” he continued. “If the Democrats are flipping that this time around and expanding that blob, I think that's a sign, because that's talking about enthusiasm in the suburbs.”

Wake and Mecklenburg counties in North Carolina

Wake and Mecklenburg counties are two of the bluest bastions in North Carolina, home to Raleigh and Charlotte, respectively.

Democrats expanded their margins in both counties last cycle, winning both counties by 6 more points in 2020 compared to 2016. Yet Mecklenburg County, which has the largest number of registered Democrats, has been a bit of a head-scratcher, with anemic turnout compared to other blue counties.

Data from the North Carolina State Board of Elections found 72 percent of the county voted during the 2020 general election, compared to 74 percent that voted in Durham County and 80 percent in Wake County.

During this year’s primary elections, close to 19 percent voted in Mecklenburg County, while 25 percent voted in Wake County and 27 percent voted in Durham. Both counties could offer clues on Democrats’ enthusiasm among their base and whether the party has addressed voting turnout concerns in Mecklenburg, specifically.

Berks County, Pa.

Of the seven battleground states, Pennsylvania has received perhaps the most attention, particularly given the state's 19 electoral votes and its critical role in Democrats’ “blue wall,” which also includes states like Michigan and Wisconsin.

Of course, experts will be watching some of the most notable swingy counties, such as Erie, Northampton and Monroe. But Berwood Yost, director of Franklin and Marshall College's Center for Opinion Research and Floyd Institute for Public Policy, which polls the state, said he’ll also be watching Berks County.

“Berks County has a sizable Hispanic community. It's also the only county in the state that Trump won in 2020 by less than 10 points,” Yost told The Hill.

“There's been a lot of talk about working-class Hispanic and African American voters moving away from Democrats. If that's true, then we'll see it in Berks County,” he added.

Berks County includes Reading, which has a large Latino and Hispanic population, and could offer a test case over whether a comedian’s controversial comments about Puerto Rico at Trump's Madison Square Garden rally last month could impact the former president.

Milwaukee and Dane counties in Wisconsin

Democrats will need to run up the numbers in Dane and Milwaukee counties to keep Wisconsin within reach. Biden expanded the margins in both counties in 2020.

“How big is the Democratic margin in votes — not in percentage, but in votes — out of Milwaukee County and out of Dane County, because those are the two largest bastions of lopsided Democratic margins,” noted Charles Franklin, director of the Marquette Law School Poll.

Meanwhile, Trump performed worse in three critical counties right outside of Milwaukee — Waukesha, Ozaukee and Washington, referred to as the WOW counties — in 2020 compared to 2016. Franklin said he’ll be watching to see whether Trump revives some of those gains in Waukesha, for example.

“Do we see Trump get 55 percent in Waukesha instead of 59, or does he do like the Republican gubernatorial candidate in 2022 did and get 59 percent there?” he asked.

Maricopa County, Ariz.

Maricopa County is arguably Arizona's single most important county, home to over 60 percent of the Grand Canyon State vote share.

The county, which includes Phoenix, went for Trump by close to 3 points in 2016 and swung to Biden by 2 points in 2020. Maricopa County has also been ground zero for election denialism after the 2020 election, with Trump contesting his loss in the pivotal county.

One of the key questions looming over the race is whether some of the voting blocs that Trump ostracized in 2020 — including suburban women, independents and moderate Republicans — come home to him this time around.

Another key question will be whether the issue set, and in particular immigration and the border, aid Trump enough in the border state.