Upset Brief · FL-21 · James T. Martin (D) vs. Brian Mast (R), incumbent
A long shot on the math: it takes a 18.6-point national wave.
<1%
odds today
<1%
odds with the plan
66,310
net votes to find
37
days left; voting starts October 24
Where
- 01+182Precinct 17 (St. Lucie County)Starting line Martin +84. 1.1% split their ticket. About 604 more ballots in 2024 than in 2022 (estimate).
- 02+132Precinct 14 (St. Lucie County)Starting line Martin +70. 1.8% split their ticket. About 491 more ballots in 2024 than in 2022 (estimate).
- 03+102Precinct 18 (St. Lucie County)Starting line Martin +75. 4.2% split their ticket. About 347 more ballots in 2024 than in 2022 (estimate).
- 04+99Precinct 19 (St. Lucie County)Starting line Martin +30. 2.3% split their ticket. About 813 more ballots in 2024 than in 2022 (estimate).
- 05+92Precinct 24 (St. Lucie County)Starting line Martin +59. 2.4% split their ticket. About 401 more ballots in 2024 than in 2022 (estimate).
- 06+62Precinct 8611 (Palm Beach County)Starting line Martin +56. 3.7% split their ticket. About 291 more ballots in 2024 than in 2022 (estimate).
The top 12 precincts carry 21% of the plan.
How
- P+3,486Persuade3,486 voters who split their ticket in recent elections and lean Mast today.
- M+1,058MobilizeAt least 7,592 people who voted in 2024 but not in 2022, in precincts where Martin's side wins at least 55 percent.
- C+333ConsolidateVoters who went third party in recent races, in the precincts that lean Martin's way.
Plus a national shift of 18.6 points of margin (61,433 votes) that no campaign controls.
What has to be true
- Martin wins 50 percent of the ticket splitters now leaning Mast.
- In Precinct 17 (St. Lucie County) and Precinct 14 (St. Lucie County), 35 percent of the people who voted in 2024 but skipped 2022 come back and vote.
- The national environment moves about 18.6 points toward Martin'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 numbers behind it
- 01Crossover regression291 precincts, R² 0.973, 71 crossover precincts identified
- 02Monte Carlo20,000 seeded simulated elections with a 7-point baseline error. 90% range of the final margin with the plan: -99,272 to -22,884 votes.
- 03Money, FEC candidate totals through July 29Martin $188,045 cash on hand; Mast $2,928,458.
- 04Call program for this list10,706 households, 32,118 dials, about 1,683 live conversations: an estimated $4,777 at published rates.
Independent analysis by The Political Group from official Florida Division of Elections precinct returns (2022 and 2024), FEC filings and published polls, as of September 26, 2026. Not affiliated with any candidate or party.