Numbers tell you who won. Maps tell you where they won—and where they didn't. Precinct-level maps reveal the geographic structure of electoral coalitions: which neighborhoods anchor each candidate's support, where the competitive margins lie, and how different contests produced different geographic patterns in the same jurisdiction.
Why Geography Matters
Election results aggregated to a jurisdiction hide essential information:
- A candidate who won 55% might have swept some neighborhoods while getting crushed in others
- A ballot measure that passed might have succeeded despite losing most of the geographic area (because the Yes votes were concentrated in high-population precincts)
- Two candidates with similar overall vote shares might have completely different geographic bases
Geographic analysis reveals these patterns. It's essential for post-election forensics, campaign targeting, and understanding how different communities within a jurisdiction vote.
Finding the Precinct-Level Map
On any jurisdiction page:
- Click the Elections tab
- Select Precinct-Level Map
The map is only available for jurisdictions with precinct-level data. If the option doesn't appear, precinct data isn't available for that jurisdiction.
Use the controls at the top to select:
- Year: Historical elections from 2014 to present (availability varies)
- Election type: General or Primary
- Race type: Statewide, Legislative, or Local
- Contest: The specific race or ballot measure to visualize
For legislative districts spanning multiple counties, use the County filter to focus on precincts from a single county.
Reading the Map
The map encodes two pieces of information through color:
Color hue shows who won each precinct:
- Blue = Democratic candidate (in partisan general elections)
- Red = Republican candidate
- Green = Yes (for ballot measures)
- Red = No (for ballot measures)
- Other colors for primaries and local races (non-partisan assignment)
Color intensity shows the margin:
- Darker = larger margin (20%+ is a "safe" precinct)
- Lighter = smaller margin (under 5% is competitive)
A dark blue precinct is a Democratic stronghold. A light blue precinct leans Democratic but could flip. A light red precinct is the mirror image—Republican-leaning but competitive.
Margin Buckets
The platform uses these categories:
| Margin | Category | What It Means |
|---|---|---|
| 0-2% | Toss-up | Could go either way |
| 2-5% | Very Competitive | Persuasion territory |
| 5-10% | Competitive | Lean toward one side |
| 10-20% | Lean | Solid but not locked |
| 20%+ | Safe | Stronghold |
The legend shows the color scale for the two leading candidates or positions.
The Results Panel
Next to the map, the results panel shows:
- Total precincts in the view
- Total votes cast
- Ranked candidates or positions with vote totals and percentages
- The overall margin
When you apply a county filter (for multi-county legislative districts), these numbers update to show only the filtered area.
Comparing Contests
One of the most powerful uses of precinct maps is comparing how the same precincts voted across different contests:
- View the Presidential race to establish partisan baseline
- Switch to a down-ballot race to see where patterns held or broke
- Look for precincts that changed color—these are ticket-splitting areas
A candidate who won precincts that their party lost at the top of the ticket built a personal coalition that exceeded partisan expectations.
Important Limitations
Darker doesn't mean more votes. A tiny precinct with 50 voters can be dark red while a huge precinct with 5,000 voters is light blue. Color intensity shows margin, not turnout volume.
Precinct boundaries change. Even between elections in the same decade, precinct lines can shift. Direct geographic comparison across years should be done cautiously.
This shows aggregate patterns, not individual behavior. A blue precinct doesn't mean every voter there voted Democratic—just that more did than didn't.
Primary elections use non-partisan colors. In California's top-two primary, all candidates appear regardless of party. Colors are assigned by vote order, not party affiliation. Check the results panel for party labels.
Relationship to Other Tools
The Precinct-Level Map shows geographic patterns for one contest at a time. For deeper analysis:
- Election Reports: Includes precinct maps plus coalition heatmaps, demographic breakdowns, and sortable precinct tables
- Precinct Analysis (under Elections → Precinct Analysis): Compares how precincts voted across two different variables with correlation statistics
Practical Applications
Identifying base vs. swing geography: Dark precincts are base territory (turnout focus). Light precincts are swing territory (persuasion focus). Campaigns allocate resources differently to each.
Understanding coalition geography: View multiple races to see which neighborhoods consistently vote together and which split depending on the contest.
Analyzing ballot measure support: See whether a measure's support was geographically concentrated or dispersed. Concentrated support may indicate coalition limitations.
Post-election debrief: After a loss, identify which precincts underperformed expectations. Were the losses concentrated in specific neighborhoods, or spread evenly?
Common Mistakes
Over-interpreting precinct boundaries: Precincts are administrative units, not communities. A precinct boundary may cut through a neighborhood arbitrarily.
Ignoring the county filter: Multi-county legislative districts can be misleading if you don't realize some precincts are grayed out because they're in a different county.
Assuming geographic consistency over time: A precinct's partisan lean can change between elections as the voters change or as different candidates appeal to different coalitions.
Confusing this with demographic analysis: The map shows how precincts voted, not who lives there. For demographic correlation, use the Precinct Analysis tool.