Ohio's Democratic primary surge was built in the cities and suburbs, not the red counties.
Ohio's Democratic share of primary ballots jumped from 33% to 47%. Gains were biggest where Harris won and less than a third as large in deep-red precincts.
of Republican-history voters voted in the Democratic primary
51,145 voters · 6.3% of D ballotsof Democratic-history voters voted in the Republican primary
25,582 voters · 2.8% of R ballotsof expected voters with no primary history voted in the Democratic primary
108,599 voters · 13.4% of D ballotsof the same group voted in the Republican primary
67,308 voters · 7.5% of R ballotsThe local majority pulled crossover voters in
Crossover rate by precinct 2024 Harris share.
R → D concentrated where Harris won; D → R in Trump country, above all the Mahoning Valley.
R → D: 1% in Trump's best precincts, 8% in Harris's
R → D climbs from 1.1% in precincts under 20% Harris to 7.9% where she topped 70%. Franklin (5.9%) and Cuyahoga (5.6%) led the big counties.
D → R: the old Democratic valley
6.3% in the reddest precincts, under 1% in the bluest. Belmont County led at 14%, followed by Jefferson, Trumbull, Tuscarawas and Mahoning, once-Democratic counties in eastern Ohio.
Four ways to slice Ohio's precincts
Republicans fell off everywhere; returning Democrats concentrated in suburban, college-educated precincts.
Dots: random sample of precincts. Lines: LOESS across all precincts, weighted by base size, with 95% bands; dashed lines are statewide rates. Existing-voter turnout: returning past primary voters minus 2022 voters who skipped 2026, as a share of the party's 2022 primary vote.
Ohio, one precinct at a time
Net crossover leans D around Columbus, Cleveland and Cincinnati and R in the Mahoning Valley and Ohio River counties.
Pinch or Ctrl/⌘-scroll to zoom, drag to pan, tap a precinct for its value. Download PNG saves the current view.
Crossover voters, by group
Point gain: group rate minus statewide rate. Shown only where the gap exceeds sampling error. Groups overlap and don't control for one another.
Three sources of the Democratic gain
The primary margin moved 426,398 votes toward Democrats. Three-quarters came from turnout among past primary voters.
Percent of each party's 2022 primary vote (voter file); margin in points of the 2022 two-party primary vote, so rows add up.
| Democratic primary | Republican primary | Margin | |
|---|---|---|---|
| 2022 primary (voter file) | 491,757 | 1,007,292 | R+515,535 |
| Switching | +57,665 | −4,363 | D+62,028 |
| Voted the other party's primary in 2022 | +36,606 | +10,204 | D+26,402 |
| Skipped 2022, last primary was the other party's | +31,263 | +22,039 | D+9,224 |
| Voted this party's primary in 2022, the other in 2026 | −10,204 | −36,606 | D+26,402 |
| Existing-voter turnout | +152,202 | −170,814 | D+323,016 |
| Skipped 2022 while registered, voted in 2024 | +120,214 | +135,451 | R+15,237 |
| Voted in 2024, registered after the 2022 deadline | +6,257 | +7,010 | R+753 |
| Skipped 2022, last voted before 2022 | +166,642 | +89,852 | D+76,790 |
| Voted in 2022, skipped 2026 | −140,911 | −403,127 | D+262,216 |
| New voters | +108,815 | +67,461 | D+41,354 |
| First primary ever, registered by the 2022 deadline | +69,636 | +46,447 | D+23,189 |
| First primary ever, registered after the 2022 deadline | +39,179 | +21,014 | D+18,165 |
| 2026 primary (voter file) | 810,439 | 899,576 | R+89,137 |
| Change | +318,682 | −107,716 | D+426,398 |
Democrats added 318,682 ballots
Returning past primary voters added 152,202 on net, first-time voters 108,815 and switchers 57,665.
Republicans lost 107,716
403,127 of their 2022 primary voters skipped 2026. Returning voters and newcomers made up 73% of that.
Both years from the voter file (2026 runs just under the official 907,273 R and 815,922 D). Skipped 2022 = registered by the Apr. 4, 2022 deadline. Issues-only ballots count as no party. New = no party primary ballot 2002–2025. 2022 had a crowded GOP Senate primary.