CA-48 · U.S. House
Open this race on The Map ↗Marni von Wilpert is narrowly favored to flip CA-48’s House seat. Predicted margin: D+4.6.
high / low: vote share (%) in the middle 80 in 100 simulations
Forecast history
Latest reading · Sep 13 · first published Sep 9 · 80% range · margin points R+3.5 to D+12.8. Methodology
Hover the line, tap it, or use the arrow keys to inspect its history.
About this series
This comparable series begins on September 9, 2026, when the model version changed to CTMM 2.2. Earlier readings remain in the archive and are not joined as voter movement; faded points before September 9, 2026 are reconstructions, not forecasts issued on those days.
Faded: CTMM 2.2 reconstructed history: computed after the fact with each date's available polls and environment, without expert ratings; not an issued forecast. Issued forecasts begin at the launch marker.
The polls
Ledger weighted average D+2.6Used by the forecast: 2 polls (60-day half-life) · measured D+1.9 · after the fitted poll-error shift D+1.92 recorded polls · 2 eligible for the aggregate · 2 with positive weight
| Fieldwork | Added | Pollster | Result | Sample |
|---|---|---|---|---|
| from 2026-08-27 | SurveyUSA ↗KGTV-TV (California) | San Diego Union-Tribune | D+3.0D 45% · R 42% | 522 LV | |
| from 2026-07-09 | Lake Research Partners ↗ | D+2.0D 48% · R 46% | 500 LV |
Recent elections
| Election | Result | Votes cast |
|---|---|---|
| 2024 · U.S. House ↗ | R+18.6 | 360,290 |
| 2022 · U.S. House ↗ | R+20.7 | 257,071 |
| 2020 · U.S. House ↗ | R+2.1 | 395,100 |
| 2018 · U.S. House ↗ | D+7.1 | 294,736 |
Historical district boundaries may differ. Margins compare Democratic and Republican vote totals. Nonstandard ballots are labeled separately.
The money
Jim Desmond ↗
R$2.3Mraised
$1.2M cash on handFiling through 06/30/2026
Marni von Wilpert ↗
D$2.2Mraised
$825K cash on handFiling through 06/30/2026
Bar length compares reported receipts in this race; the tick marks cash on hand. A missing filing stays blank rather than becoming $0.
One more fundraising reportCall the Map · $0
The candidates are comfortably out-fundraising the website covering them. A little rude, perhaps, but statistically unsurprising.
- Received so far
- $0
- Measured compute
- $26,188.58
Ko-fi and Buy Me a Coffee receipts are counted through Sep 1, 2026. Measured compute prices model runs at standard published API rates; it is not what I paid. Hosting, data and subscriptions, the domain and my own time are not counted. Donations buy gratitude, never a forecast adjustment.
Outside spending
Support + opposition · separate from receiptsFor and against Marni von Wilpert$2.6M
8 spending groups
| Group | For | Against |
|---|---|---|
| Project 218 | $900K | $0 |
| Serving CA | $0 | $653K |
| Elect Democratic Women | $390K | $0 |
| Equality PAC | $381K | $0 |
| Women Vote | $139K | $0 |
| VETERANS FOR TRUTH PAC | $0 | $52K |
| SEIU COPE (Service Employees International Union Committee On Political Education) | $49K | $0 |
| NO GOING BACK PAC INC. | $0 | $29K |
For and against Jim Desmond$337K
1 spending group
| Group | For | Against |
|---|---|---|
| 48Th Accountability Project | $0 | $337K |
Includes primary spending. Opposition is recorded against its named target; no benefit to another candidate is assumed.
$3.8M in outside spending on earlier candidates.
FEC filings · through 06/30/2026 · Definitions & method
Race context
- Forecast votes cast
- 221,571
- 2024 presidential margin
- D+3.5