Top-two primary
All candidates run in one primary regardless of party and the two with the most votes advance, so two candidates of the same party can meet in November. The forecast then marks the seat as safe for that party.
California › U.S. House of Representatives · November 3, 2026 · Updated Oct 16, 2026
California's 18th District
Top twoLofgren is very likely to win: Lofgren wins in more than 99 of every 100 simulations.
Lofgren (D)
>99%
chance of winning
Lewis (R)
<1%
- Average margin
- D+40.0
- 80% of outcomes
- D+31 to D+50
- Partisan lean
- D+33
- Polls
- No pollsmodel only
Lofgren is very likely to win: Lofgren wins in more than 99 of every 100 simulations.
Lofgren (D)
>99%
chance of winning
Lewis (R)
<1%
- Average margin
- D+38.9
- 80% of outcomes
- D+27 to D+52
- Partisan lean
- D+33
- Polls
- No pollsmodel only
How this race is decided
Range of outcomes
Final margin across our simulations; the white dashes mark the middle 80%.
The candidates
DemocraticIncumbent
Zoe Lofgren
Incumbent U.S. representative
- Experience
- Statewide office or Congress
- Raised
- $2M
- From individuals
- $1.2M
- Spent
- $1.5M
- Cash on hand
- $713.8K
Money: FEC, through Sep 30, 2026.
Republican
Shane Lewis
U.S. Marine veteran
- Experience
- No elected office
- Raised
- $107K
- From individuals
- $41.5K
- Spent
- $103.7K
- Cash on hand
- $3.3K
Money: FEC, through Sep 30, 2026.
What goes into the forecast
Every ingredient's estimate of the final margin.
- National environment
- D+9.5Election Day forecast; federal races run in it
- Swing reaching this office
- 78%Of a shift in the environment, from past House races since 2016
- Pacific adjustment
- −1.2How House races in the region have run against lean and environment lately
Each estimate is a margin before national and statewide uncertainty is simulated. Horizon blends polls, fundamentals and a little of the similar-places estimate, weighting each by how precise it is; Pulse uses polls and similar places only.
Fundamentals inputs
| Incumbency (+1 D, −1 R) | 1 |
| Fundraising edge (log ratio of individual money) | 2.1 |
| Elected-experience edge | 1 |
| First-term incumbent | 0 |
| Seat's last result vs. expectation | 0 |
| Incumbent's last result vs. expectation | 0 |
Polls
No public polls of this race. The forecast relies on fundamentals and on polling of similar places.
The district
Lean D+33: how much more Democratic or Republican than the nation it votes for president.
Presidential vote
Precinct results re-aggregated to the current district lines.
Who lives here
- Population
- 742,328
- People per km²
- 48
- Adults with a B.A.+
- 24%
- White, no degree
- 13%of adults
- White 18%
- Hispanic 65%
- Black 2%
- Asian 11%
- Other / multiracial 3%
American Community Survey 2020–2024, aggregated from census tracts.
Past results
Results in the same-numbered district; earlier elections may have used different lines.
2024 Earlier district lines
228,375 votes · D+29.3✓ Zoe Lofgren (D)64.6%
Peter D. Hernandez (R)35.4%
2024 President Vote in this district
228,545 two-party votes · D+29.3 · D+30.8 vs. the nation✓ Kamala Harris (D)64.7%
Donald Trump (R)35.3%
2022 Earlier district lines
151,513 votes · D+31.7✓ Zoe Lofgren (D)65.9%
Peter Hernandez (R)34.1%
2020 Earlier district lines
344,139 votes · Uncontested by the other party✓ Anna G Eshoo (D)63.2%
Rishi Kumar (D)36.8%
2020 President Vote in this district
259,179 two-party votes · D+43.5 · D+38.9 vs. the nation✓ Joe Biden (D)71.7%
Donald Trump (R)28.3%
2018 Earlier district lines
302,238 votes · D+49.0✓ Anna G Eshoo (D)74.5%
Christine Russell (R)25.5%
2016 Earlier district lines
323,930 votes · D+42.3✓ Anna G Eshoo (D)71.1%
Richard B Fox (R)28.9%
2016 President Vote in this district
196,690 two-party votes · D+49.9 · D+47.6 vs. the nation✓ Hillary Clinton (D)74.9%
Donald Trump (R)25.1%