DataPorium data identify 31 swing counties with at least 50,000 votes in 13 states that hold a Senate or governor race on November 3, 2026: 23 voted for different parties across the 2016, 2020 and 2024 presidential elections, and 8 more were decided by less than 3 points in 2024 [1][2][3]. The closest was Bucks County, Pennsylvania, which went R+0.1 in 2024 after D+4.4 in 2020 [1][2]. Pennsylvania and Texas have 7 counties each on the list, Michigan 4, Ohio 3 and North Carolina 2.
How were the swing counties chosen?
The list uses certified presidential results by county and one rule, applied the same way to both parties. A county is included when it cast at least 50,000 presidential votes in 2024 and meets one of two tests:
- Changed party: the county's presidential winner was not the same party in all three of 2016, 2020 and 2024 [1][2][3].
- Close in 2024: the 2024 presidential margin was under 3 points, without a change of party [1].
The margin is the Republican share of the vote minus the Democratic share, in percentage points. R+2.4 means the Republican candidate led by 2.4 points; D+2.4 means the Democratic candidate led by 2.4 points. "To watch" here means only that a county was close or changed party in recent elections. It is not a forecast.
The 13 states reviewed are Arizona, Georgia, Iowa, Maine, Michigan, Minnesota, Nevada, New Hampshire, North Carolina, Ohio, Pennsylvania, Texas and Wisconsin. Each holds a 2026 Senate race, a 2026 governor race, or both. Georgia, Iowa, Maine, Michigan, Minnesota, New Hampshire, Ohio and Texas hold both; Arizona, Nevada, Pennsylvania and Wisconsin hold a governor race but no Senate race; North Carolina holds a Senate race but no governor race [5][6]. In total, 35 Senate seats, including special elections in Ohio and Florida, and 36 governorships are on the 2026 ballot [5][6].
Georgia, Minnesota and Wisconsin have no county that met either test at the 50,000-vote size. In Minnesota and Wisconsin the nearest were Anoka County, Minnesota, at R+4.4 and Winnebago County, Wisconsin, at R+4.7 in 2024 [1].
Which large counties changed party between 2016 and 2024?
Twenty-three counties voted for different parties across the last three presidential elections. Sixteen voted Democratic in 2020 and Republican in 2024. Five voted Republican in 2016 and Democratic in both 2020 and 2024. Two, Lorain County and Mahoning County in Ohio, voted Democratic in 2016 and Republican in 2020 and 2024 [1][2][3]. The last column shows the county's margin in the state's 2022 U.S. Senate race, or the governor race where there was no Senate race (Maine and Texas) [4].
| County | 2016 | 2020 | 2024 | 2022 statewide |
|---|---|---|---|---|
| Bucks County, Pennsylvania | D+0.8 | D+4.4 | R+0.1 | D+7.4 (Senate) |
| Montgomery County, Ohio | R+0.7 | D+2.2 | D+0.5 | D+1.7 (Senate) |
| New Hanover County, North Carolina | R+3.9 | D+2.1 | D+0.6 | D+1.9 (Senate) |
| Monroe County, Pennsylvania | D+0.8 | D+6.4 | R+0.8 | D+6.0 (Senate) |
| Erie County, Pennsylvania | R+1.6 | D+1.0 | R+1.0 | D+9.4 (Senate) |
| Nash County, North Carolina | R+0.2 | D+0.2 | R+1.8 | R+6.7 (Senate) |
| Northampton County, Pennsylvania | R+3.8 | D+0.7 | R+1.8 | D+5.2 (Senate) |
| Muskegon County, Michigan | D+1.5 | D+0.6 | R+1.8 | not available |
| Webb County, Texas | D+51.6 | D+23.3 | R+2.2 | D+24.0 (governor) |
| Rockingham County, New Hampshire | R+5.8 | D+2.1 | R+2.4 | D+3.1 (Senate) |
| Williamson County, Texas | R+9.7 | D+1.4 | R+2.4 | R+0.6 (governor) |
| Kennebec County, Maine | R+3.6 | D+0.2 | R+2.7 | D+4.1 (governor) |
| Hillsborough County, New Hampshire | R+0.2 | D+7.7 | D+2.9 | D+8.7 (Senate) |
| Hidalgo County, Texas | D+40.5 | D+17.1 | R+2.9 | D+18.3 (governor) |
| Saginaw County, Michigan | R+1.1 | D+0.3 | R+3.3 | not available |
| Maricopa County, Arizona | R+2.8 | D+2.2 | R+3.5 | D+6.4 (Senate) |
| Scott County, Iowa | D+1.5 | D+3.2 | R+3.9 | R+3.6 (Senate) |
| Tarrant County, Texas | R+8.6 | D+0.2 | R+5.1 | R+4.1 (governor) |
| Kent County, Michigan | R+3.1 | D+6.1 | D+5.4 | not available |
| Hays County, Texas | R+0.8 | D+10.8 | D+5.6 | D+11.0 (governor) |
| Lorain County, Ohio | D+0.1 | R+2.4 | R+5.7 | D+2.4 (Senate) |
| Cameron County, Texas | D+32.5 | D+13.2 | R+5.8 | D+9.6 (governor) |
| Mahoning County, Ohio | D+3.3 | R+1.9 | R+9.4 | R+3.5 (Senate) |
Source: DataPorium Election Results, certified presidential results by county for 2016, 2020 and 2024 and 2022 Senate and governor results by county [1][2][3][4]. Sorted by the size of the 2024 margin. Michigan held no Senate race in 2022, and county results for its 2022 governor race are not included in the data.
Two patterns stand out. The three Texas border counties on the list, Webb, Hidalgo and Cameron, moved the most: Webb County went from D+51.6 in 2016 to R+2.2 in 2024, and Hidalgo County from D+40.5 to R+2.9 [1][3]. The suburban counties that changed party moved by smaller amounts in both directions: Hays County, Texas, went from R+0.8 to D+5.6 and Kent County, Michigan, from R+3.1 to D+5.4, while Rockingham County, New Hampshire, went from R+5.8 to D+2.1 and back to R+2.4 [1][2][3]. The full history of any county is on its DataPorium page, for example Bucks County, Pennsylvania or Maricopa County, Arizona.
Which large counties were closest in 2024 without changing party?
Eight more counties voted for the same party in all three presidential elections but were decided by less than 3 points in 2024. Seven voted Democratic each time and one, Grand Traverse County, Michigan, voted Republican each time [1][2][3].
| County | 2016 | 2020 | 2024 | 2022 statewide |
|---|---|---|---|---|
| Washoe County, Nevada | D+1.2 | D+4.5 | D+1.0 | D+4.5 (Senate) |
| Black Hawk County, Iowa | D+7.4 | D+8.8 | D+1.2 | D+1.9 (Senate) |
| Fort Bend County, Texas | D+6.6 | D+10.6 | D+1.6 | D+4.7 (governor) |
| Grand Traverse County, Michigan | R+12.5 | R+3.0 | R+1.7 | not available |
| Clark County, Nevada | D+10.7 | D+9.4 | D+2.6 | D+7.9 (Senate) |
| Lehigh County, Pennsylvania | D+4.7 | D+7.6 | D+2.7 | D+10.2 (Senate) |
| Lackawanna County, Pennsylvania | D+3.5 | D+8.4 | D+2.8 | D+15.7 (Senate) |
| Centre County, Pennsylvania | D+2.4 | D+4.8 | D+2.8 | D+7.6 (Senate) |
Source: DataPorium Election Results, certified results [1][2][3][4].
Maricopa County, Arizona, is the largest county on either list, with 2,061,574 presidential votes in 2024, followed by Clark County, Nevada, with 1,031,223 [1]. The smallest are Grand Traverse County, Michigan, with 62,772 votes and Black Hawk County, Iowa, with 62,906 [1].
What did the 2022 midterm show in these counties?
The 2022 Senate and governor races are the most recent midterm results for these counties, with different candidates than the presidential races. In 26 of the 27 counties that have a 2022 statewide result in the data, the 2022 margin was more Democratic than the county's 2024 presidential margin [1][4]. The gap ranged from 0.3 points in Scott County, Iowa (R+3.6 in 2022, R+3.9 in 2024) to 26.2 points in Webb County, Texas (D+24.0 in 2022, R+2.2 in 2024). The exception was Nash County, North Carolina, which was more Republican in the 2022 Senate race (R+6.7) than in the 2024 presidential race (R+1.8) [1][4].
Statewide results differed as well. In 2022 Republicans won the Senate races in Ohio by 6.1 points, North Carolina by 3.2 points, Wisconsin by 1.0 point and Iowa by 12.2 points, and Democrats won the Senate races in Pennsylvania by 4.9 points, Arizona by 4.9 points, New Hampshire by 9.2 points and Nevada by 0.8 points [4]. In the governor races used for the table, Republicans won Texas by 10.9 points and Democrats won Maine by 13.1 points [4]. Turnout also differs between cycles: Maricopa County cast 1,553,939 votes in the 2022 Senate race and 2,061,574 in the 2024 presidential race [1][4].
Thirty-one large counties in states with 2026 Senate or governor races either changed party between 2016 and 2024 or were decided by less than 3 points in 2024, led by Bucks County, Pennsylvania, at R+0.1.
Frequently asked questions
What is a swing county?
A swing county is a county whose voters have supported different parties in recent elections or whose results are usually close. This list uses two tests: a change of presidential party across 2016, 2020 and 2024, or a 2024 margin under 3 points, for counties with at least 50,000 votes [1][2][3].
Which large county was closest in the 2024 presidential election?
Among the counties reviewed, Bucks County, Pennsylvania, was closest at R+0.1 out of 401,028 votes, after voting D+4.4 in 2020 and D+0.8 in 2016 [1][2][3].
Which states have Senate and governor races in 2026?
35 Senate seats, including special elections in Ohio and Florida, and 36 governorships are on the November 3, 2026 ballot. Among the 13 states reviewed, 8 have both, 4 have only a governor race and North Carolina has only a Senate race [5][6].
Where can I see results for a single county?
Each county has a DataPorium page with every presidential result since 2000 and recent Senate, House and governor results, for example Rockingham County, New Hampshire [1].
Sources & References
- [1] DataPorium Election Results (2024 presidential results by county)
- [2] DataPorium Election Results (2020 presidential results by county)
- [3] DataPorium Election Results (2016 presidential results by county)
- [4] DataPorium Election Results (2022 U.S. Senate and governor results by county)
- [5] Ballotpedia, United States Senate elections, 2026 (accessed October 13, 2026)
- [6] Ballotpedia, Gubernatorial elections, 2026 (accessed October 13, 2026)
