California · U.S. House · District 10 · November 3, 2026

What it would take for Jeff Frese.

DeSaulnier starts 30.7 points ahead on our starting line from recent official results. Campaign work can move about 4,277 net votes toward Frese, a 1.5-point gain. Winning outright would take a 29.2-point national wave on top of that. Here is the plan that makes Frese the one standing if one comes.

89,722

net votes between Frese and a win

days to election day. Mail voting opens October 5.

30.7 pts

DeSaulnier lead, our starting line from recent results

In short

One-page brief ›All California races ranked ›

A long shot on the math: it takes a 29.2-point national wave.

Odds today0%

Odds with the plan0%

Net votes to find89,722

WhereUnincorporated Contra Costa County, Danville, Walnut Creek

Underdog UpdateSeptember 26, 2026. Underdog plan published. Starting line: DeSaulnier +30.7. Jeff Frese needs 89,722 net votes. Odds 0% today, 0% with the plan.

The number

146,261 votes.

That is half of the 292,520 ballots we expect in this race, plus one. Where Frese stands today, and what is missing:

99,443 Jeff Frese baseline

189,165 Mark DeSaulnier baseline

Starting line: a weighted blend of the official 2022 and 2024 results in this district (President, U.S. Senate, Governor, Attorney General). No 2026 polls have been published. 2026 turnout modeled on 2022, the last midterm.

The odds

0% today. A wave changes that.

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.

Frese wins in

of 20,000 simulated elections

With no plan

How much of what history allows the campaign achieves100%

The plan on this page sits at 100%. Median outcome at this setting: Frese short by 85,444.

Each simulation draws the starting line with an error of 7 points of margin (no 2026 polls, so the starting line comes from history and carries more error) 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.

Three moves

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.

Persuade

3,807

net votes in the plan, from a pool of 3,807

Who. 3,807 voters who split their ticket in recent elections and lean DeSaulnier today.

How. Live conversations on the call list that matters: voters who crossed party lines, plus the undecided. Frese needs to win 50 percent of the ones now leaning DeSaulnier.

Mobilize

net votes in the plan, from a pool of 0

Who. There are almost no cities and unincorporated areas Frese's side carries, so turnout alone cannot help here.

How. Voter ID calls to people who voted in 2024 and skipped 2022, then a ballot chase until each one has voted.

Consolidate

470

net votes in the plan, from a pool of 1,343

Who. Voters who went third party in recent races, in the cities and unincorporated areas that lean Frese'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: 4,277 net votes against a gap of 89,722. Still 85,445 short. The rest needs a national shift of about 29.2 points that no campaign controls.

Where it is won

12 cities and unincorporated areas carry 95% of it.

Ranked by the net votes each one gives the plan. The darker the county, the more of the upset lives there.

Fewer net votesMore net votes for the upset

01
Unincorporated Contra Costa Countypersuade
Starting line DeSaulnier +17. 2.7% split their ticket.
+704
02
Danvillepersuade
Starting line DeSaulnier +20. 4.7% split their ticket.
+549
03
Walnut Creekpersuade
Starting line DeSaulnier +46. 2.9% split their ticket.
+529
04
Concordpersuade
Starting line DeSaulnier +33. 1.8% split their ticket.
+411
05
San Ramonpersuade
Starting line DeSaulnier +31. 2.1% split their ticket.
+350
06
Lafayettepersuade
Starting line DeSaulnier +48. 4.5% split their ticket.
+322
07
Orindapersuade
Starting line DeSaulnier +51. 4.5% split their ticket.
+253
08
Brentwoodpersuade
Starting line DeSaulnier +10. 1.7% split their ticket.
+240
09
Martinezpersuade
Starting line DeSaulnier +35. 2.0% split their ticket.
+194
10
Moragapersuade
Starting line DeSaulnier +46. 4.5% split their ticket.
+193
11
Pleasant Hillpersuade
Starting line DeSaulnier +43. 2.1% split their ticket.
+177
12
Unincorporated Alameda Countypersuade
Starting line DeSaulnier +38. 0.9% split their ticket.
+146

What the numbers say that the polls do not

The hidden path.

Unincorporated Contra Costa County carries the most.

Unincorporated Contra Costa County gives this plan more net votes than any other place: 704. It sits at DeSaulnier +17 on our starting line, and 2.7 percent of its voters split their ticket in recent elections.

Danville splits its ticket the most.

Of the cities and unincorporated areas in this plan, Danville has the highest share of ticket splitters: 4.7 percent. That is where a persuasion call is most likely to reach someone open to crossing over.

The honest math.

Every lever at its historical ceiling moves 4,277 net votes. The gap is 89,722. That is the measure of what a strong campaign adds: 1.5 points of margin, and first position if the national mood breaks.

The evidence

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 Frese's side lost voters it won further up the ballot.

Precincts: 751
Slope: 0.950
R²: 0.948
Residual SD: 4.2 pts
Crossover precincts: 294

Weighted least squares, one point per precinct, weighted by ballots cast. Orange precincts sit more than one residual standard deviation below the line: Frese's side did worse there in this race than the top of the ticket predicts. Hover any dot for the precinct.

The next 37 days

Voting starts October 5.

Now to October 4
Find them
Voter ID calls across the persuasion list in these cities and unincorporated areas. Every conversation tags the voter: with Frese, with DeSaulnier, or undecided. The undecided become the persuasion universe; the supporters become the ballot chase list.
October 5 to 16
Persuade
Second conversations with every undecided and soft voter, built around the one issue they named on the first call. The goal is 3,807 net votes from people who have crossed party lines before.
October 17 to 26
Bank 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 2
Turn them out
The drop-off voters: people who voted in 2024 and skipped 2022. At least 0 of them live where Frese is favored. Ballots postmarked by November 3 count if they arrive by November 10.
November 3
Election 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.

What has to be true

No wishful thinking.

Official results in this district: Harris carried the 2024 presidential race by 33.5 points; Schiff carried the 2024 U.S. Senate race by 28.7 points; Newsom carried the 2022 governor's race by 28.8 points.

Frese wins 50 percent of the ticket splitters now leaning DeSaulnier.
The national environment moves about 29.2 points toward Frese's side between now and November 3.
No 2026 public poll exists for this race, so the starting line is a weighted blend of official recent results; the first real poll will move it.

The work

971 conversations.

That is how many live voter conversations this plan takes: about 18,540 dials to 6,180 households, before the last ballot is cast.

6,180

households on the target list

19K

dials across three attempts

971

live conversations: persuasion, voter ID, ballot chase

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.

HyperPhonebank

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 $3,219 at our published rates: 6,180 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.

Run this plan How HyperPhonebank works ›Size your own program ›

The candidates

Who is on the ballot.

Underdog

Jeff Frese (R)

Moraga businessman who founded the keto snack brand Fat Snax in his own kitchen, grew it into a national brand and sold it, and has run consumer companies since.

Campaign site ›FEC filings ›

Favorite · incumbent

Mark DeSaulnier (D)

U.S. Representative since 2015 who previously served on the Concord City Council, the Contra Costa County Board of Supervisors, and in the California State Assembly and State Senate. He is a graduate of the College of the Holy Cross and lives in Concord.

Cash on hand $586,497 and $567,258 raised since January 1, 2025, per FEC reports through June 30, 2026.

Campaign site ›FEC filings ›Wikipedia ›

Underdog Updates

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, 2026
Underdog plan published
Starting line: DeSaulnier +30.7. Jeff Frese needs 89,722 net votes. Odds 0% today, 0% with the plan.

Questions

Can Jeff Frese win California's 10th Congressional District in 2026?

Only with help from the national environment. Campaign work can move about 4,277 net votes; the gap is 89,722. The rest would take a 29.2-point national shift.

Where are the votes Jeff Frese needs?

Ranked by net votes in the plan: Unincorporated Contra Costa County, Danville, Walnut Creek, Concord, San Ramon. 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 Jeff Frese need to persuade?

About 1,904 voters who lean Mark DeSaulnier today, each worth two votes of margin when they switch. That is 50 percent of the 3,807 persuadable voters leaning Mark DeSaulnier.

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 (7 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.