How Jim Desmond wins.
von Wilpert starts 2.8 points ahead on our starting line from 2026 polls. Desmond needs 6,322 net votes, and the math closes using 35 percent of what history allows. The most net votes are in Temecula, Unincorporated San Diego County and San Marcos.
Desmond can win. The math closes using 35 percent of what history allows.
113,383 votes.
That is half of the 226,764 ballots we expect in this race, plus one. Where Desmond stands today, and what is missing:
Starting line: von Wilpert +2.8 among decided voters, from published 2026 polls, applied to each place's pattern in the 2022 and 2024 official returns. 2026 turnout modeled on 2022, the last midterm.
29% today. 51% with the plan.
We ran this race 20,000 times with realistic error on every assumption. Drag the slider to see the odds move as the campaign captures more of what history says is available.
Each simulation draws the starting line with an error of 5 points of margin (the starting line comes from 2026 polls) and lets the plan over- or under-deliver by 30 percent. Seeded and reproducible; the method and data are at the bottom of the page.
The gap closes three ways.
Change minds. Bring out voters who skip midterms. Win back the third-party vote. Every pool below is counted from official precinct returns and published polls.
Who. Ticket splitters and the 13 percent still undecided in the latest poll: 16,382 leaning von Wilpert today.
How. Live conversations on the call list that matters: voters who crossed party lines, plus the undecided. Desmond needs to win 18 percent of the ones now leaning von Wilpert.
Who. At least 40,170 people who voted in 2024 but not in 2022, in cities and unincorporated areas where Desmond's side wins at least 55 percent.
How. Voter ID calls to people who voted in 2024 and skipped 2022, then a ballot chase until each one has voted.
Who. Voters who went third party in recent races, in the cities and unincorporated areas that lean Desmond's way.
How. A direct appeal to voters who went third party last time. They have already shown they will leave the two-party default.
Together: 6,638 net votes against a gap of 6,322. That is a win.
5 cities and unincorporated areas carry 100% of it.
Ranked by the net votes each one gives the plan. The darker the county, the more of the upset lives there.
- 01+2,765TemeculapersuadeStarting line Desmond +13. 2.3% split their ticket.
- 02+1,931Unincorporated San Diego CountypersuadeStarting line Desmond +11. 2.2% split their ticket.
- 03+909San MarcospersuadeStarting line von Wilpert +10. 1.8% split their ticket.
- 04+795Unincorporated Riverside CountymobilizeStarting line Desmond +18. 1.3% split their ticket. About 21,984 more ballots in 2024 than in 2022 (estimate).
- 05+239Indian WellspersuadeStarting line Desmond +19. 3.9% split their ticket. About 373 more ballots in 2024 than in 2022 (estimate).
The hidden path.
Temecula carries the most.
Temecula gives this plan more net votes than any other place: 2,765. It sits at Desmond +13 on our starting line, and 2.3 percent of its voters split their ticket in recent elections.
Unincorporated Riverside County is a turnout race.
Desmond's side leads Unincorporated Riverside County by about 18 points on our starting line, and it cast about 21,984 more ballots in 2024 than in 2022 (an estimate). Roughly that many of its 2024 voters sat out the last midterm; bringing enough of them back nets 720 votes there.
Indian Wells splits its ticket the most.
Of the cities and unincorporated areas in this plan, Indian Wells has the highest share of ticket splitters: 3.9 percent. That is where a persuasion call is most likely to reach someone open to crossing over.
Desmond has the cash edge.
As of June 30, 2026, the close of the latest FEC reporting period, Desmond had $1.23 million in cash on hand to von Wilpert's $825K. The underdog can fund the contact this plan takes.
Where voters cross over.
Every dot is a precinct. If no one split a ticket, every dot would sit on the line. The orange ones are where Desmond's side lost voters it won further up the ballot.
- Precincts
- 653
- Slope
- 1.010
- R²
- 0.981
- Residual SD
- 3.3 pts
- Crossover precincts
- 119
Weighted least squares, one point per precinct, weighted by ballots cast. Orange precincts sit more than one residual standard deviation below the line: Desmond's side did worse there in this race than the top of the ticket predicts. Hover any dot for the precinct.
Voting starts October 5.
- Now to October 4Find them
Voter ID calls across the persuasion list in these cities and unincorporated areas. Every conversation tags the voter: with Desmond, with von Wilpert, or undecided. The undecided become the persuasion universe; the supporters become the ballot chase list.
- October 5 to 16Persuade
Second conversations with every undecided and soft voter, built around the one issue they named on the first call. The goal is 5,751 net votes from people who have crossed party lines before.
- October 17 to 26Bank the ballots
California mails a ballot to every active registered voter starting October 5. Ballots postmarked by November 3 count if they arrive by November 10, and conditional voter registration is open through Election Day. Chase every supporter's mail ballot request until it is returned, and move supporters to early voting while it is open.
- October 27 to November 2Turn them out
The drop-off voters: people who voted in 2024 and skipped 2022. At least 40,170 of them live where Desmond is favored. Ballots postmarked by November 3 count if they arrive by November 10.
- November 3Election day
Polls and vote centers are open until 8 p.m. California allows conditional voter registration through Election Day. The last calls go to identified supporters who have not voted, with their polling place in hand.
No wishful thinking.
Official results in this district: Harris carried the 2024 presidential race by 3.4 points; Schiff carried the 2024 U.S. Senate race by 0.7 points; Dahle carried the 2022 governor's race by 2.2 points.
- Desmond wins 18 percent of the ticket splitters and undecided voters now leaning von Wilpert.
- In Unincorporated Riverside County and Indian Wells, 12 percent of the people who voted in 2024 but skipped 2022 come back and vote.
- No national wave is required. The plan closes at 35 percent of what recent California results show is possible.
- The starting line comes from published 2026 polls, including campaign or party sponsored polls where those are the only ones; if the true gap is different, so is the plan.
2,626 conversations.
That is how many live voter conversations this plan takes: about 50,111 dials to 16,704 households, before the last ballot is cast.
Call list: every ticket splitter and undecided voter in the targeted places (you cannot tell which way they lean before the call), every targeted drop-off voter, and the reachable third-party voters. About 69 households for every 100 voters on the list, three attempts each, and a 5.24 percent live answer rate per attempt, the per-program average across 1.2 million real 2026 dials in our published benchmarks.
We run this list.
Calls are the voter ID and ballot chase engine of this plan. They find the persuadable voters and the supporters, so every other dollar lands on the right door. The full call program for this list is an estimated $6,623 at our published rates: 16,704 households, three attempts each.
Professional live callers working exactly these precincts: persuasion on the ticket splitters, voter ID on the fence, ballot chase on every absentee request until it is returned. A live dashboard shows every conversation as it happens. Days to launch, not weeks.
Who is on the ballot.
Jim Desmond (R)
San Diego County Supervisor for the 5th District since 2019 and board vice chair from 2020 to 2021, after serving as mayor of San Marcos from 2006 to 2018. A U.S. Navy veteran and retired aviator.
Cash on hand $1,230,031 and $2,258,836 raised since January 1, 2025, per FEC reports through June 30, 2026.
Marni von Wilpert (D)
San Diego City Councilmember for District 5 since 2020, a former city prosecutor and Obama administration workers' rights attorney, and a Peace Corps alumna. Raised in Scripps Ranch, she holds a B.A. from UC Berkeley and a J.D. from Fordham University School of Law.
Cash on hand $825,012 and $2,174,872 raised since January 1, 2025, per FEC reports through June 30, 2026.
What changed, and when.
We re-run this race as new polls, fundraising reports and early vote counts arrive. Every change to the numbers is logged here.
- September 26, 2026Underdog plan published
Starting line: Wilpert +2.8. Jim Desmond needs 6,322 net votes. Odds 29% today, 51% with the plan.
Questions
Can Jim Desmond win California's 48th Congressional District in 2026?
Yes, on the math. Jim Desmond needs 6,322 net votes, and recent California results show about 18,910 are reachable through persuasion, turnout and third-party voters. The plan closes the gap using 35 percent of that.
Where are the votes Jim Desmond needs?
Ranked by net votes in the plan: Temecula, Unincorporated San Diego County, San Marcos, Unincorporated Riverside County, Indian Wells. Persuadable voters are counted from ticket splitting in 2022 and 2024 official returns; turnout targets are people who voted in 2024 and skipped 2022.
How many voters does Jim Desmond need to persuade?
About 2,876 voters who lean Marni von Wilpert today, each worth two votes of margin when they switch. That is 18 percent of the 16,382 persuadable voters leaning Marni von Wilpert.
When does early voting start in California in 2026?
California mails every active registered voter a ballot starting October 5, 2026. Ballots postmarked by November 3 count if they arrive by November 10, vote centers open before Election Day, and conditional voter registration is available through Election Day.
Who made this analysis?
The Political Group, an independent campaign services firm, from official California Secretary of State precinct returns, Census data, FEC filings and published polls. It is not affiliated with any candidate or party.
Method and sources
Precinct math from official California Secretary of State returns for 2022 and 2024, projected onto current district lines. Polls, ratings and fundraising as published on the dates shown. This is independent analysis by The Political Group, as of September 26, 2026. It is not affiliated with or endorsed by any candidate or party, and it is written for every campaign that starts behind.
Statistics: a weighted least squares crossover regression on every precinct, and 20,000 seeded Monte Carlo simulations. The baseline error (5 points of margin) and plan efficacy spread (30 percent) are our stated assumptions. Download the precinct data (CSV, ready for JASP). Free to cite under CC BY 4.0 with a link to this page.
- California Secretary of State, Statement of Vote
- California Statewide Database (precinct results and block conversions)
- Proposition 50 congressional districts (AB 604)
- FEC candidate filings (OpenFEC)
- 2026 voter contact benchmarks (The Political Group)
- Poll: SurveyUSA (2026-08-27 to 2026-09-01)
- Poll: Lake Research Partners (2026-07-09 to 2026-07-14)