# Will Joseph Arminio be the Republican nominee for Delaware at-large congressional district

> Closed. Last odds frozen 3 d ago — final outcome on the venue.

URL: https://simplefunctions.dev/odds/dealr
Updated: 2026-09-04T07:20:52.385Z
Category: politics · Topic: election-2026
Status: historical
Closes: 2027-09-15

## Headline

- Probability: 25% (liquidity-weighted across 4 contracts)
- Venue: Kalshi (4 contracts)
- 24h volume: $246

## Bound contracts (4)

| Outcome | Price | 24h | Volume | Venue | Slug |
|---|---|---|---|---|---|
| Earl Cooper | 54¢ | +1pp | $140 | kalshi | /markets/will-earl-cooper-be-the-republican-nominee-for-del-kalshi-kxdealr-26-ecoo |
| Joseph Arminio | 5¢ | ±0 | $98 | kalshi | /markets/will-joseph-arminio-be-the-republican-nominee-for-kalshi-kxdealr-26-jarm |
| John J. Whalen III | 35¢ | −2pp | $8 | kalshi | /markets/will-john-j-whalen-iii-be-the-republican-nominee-f-kalshi-kxdealr-26-jwha |
| Gavin Solomon | 5¢ | — | $0 | kalshi | /markets/will-gavin-solomon-be-the-republican-nominee-for-d-kalshi-kxdealr-26-gsol |

## 30-day trajectory

| Day | Aggregate |
|---|---|
| 2026-08-08 | 54 |
| 2026-08-24 | 28 |
| 2026-08-31 | 31 |
| 2026-09-02 | 32 |

_24 days of price history captured. Each row is the daily mean of intraday 5-min captures._

## What moved the line

- 2026-08-31 · Earl Cooper +6pp 50→56¢ · kalshi
- 2026-09-01 · John J. Whalen III +6pp 32→38¢ · kalshi
- 2026-09-01 · Earl Cooper −3pp 56→53¢ · kalshi
- 2026-08-31 · John J. Whalen III −3pp 35→32¢ · kalshi

## Analysis

This probability reflects the likelihood that Joseph Arminio becomes the Republican Party's nominee for Delaware's at-large congressional seat in the 2026 election cycle. At 23%, Arminio ranks as a secondary contender behind frontrunner Earl Cooper, who commands 73% implied probability. The gap between Arminio and Cooper suggests market participants view Cooper as substantially more likely to secure the nomination based on current positioning or visibility. The main factors shaping this level include the strength of each candidate's campaign infrastructure, fundraising performance, endorsement patterns among party leadership, and any strategic decisions about whether multiple strong candidates remain in the race through the primary process. The nomination will be resolved once Delaware Republicans formally select their nominee, likely through a primary election or party convention depending on state procedures.

### Key factors

- Earl Cooper's commanding 73% market share suggests he is perceived as the clear frontrunner, leaving limited probability for alternative candidates including Arminio
- Joseph Arminio at 23% implies he is viewed as a viable but substantially weaker second option compared to Cooper among Republican primary voters or delegates
- The four-candidate field shows 73% + 7% + 7% + 5% = 92%, indicating 8% residual probability for other unnamed candidates or measurement uncertainty
- Relative trading volume ($371 in 24h volume for Cooper vs. $0 for Arminio) suggests significantly more market confidence and interest in Cooper as the likely nominee
- Primary election timing and campaign developments (endorsements, fundraising reports, polling data) represent key catalysts that could shift probabilities among these candidates before the formal nomination occurs

## Methodology

Probability is **liquidity-weighted** across all bound Kalshi/Polymarket contracts: Σ(price × volume) ÷ Σ(volume). 30-day trajectory uses the daily mean of intraday 5-min captures. 24h delta = today's mean − yesterday's mean. Movement events are ≥3pp daily moves in the last 7 days.

## How to use this data

- HTML: https://simplefunctions.dev/odds/dealr
- JSON: https://simplefunctions.dev/api/public/odds?slug=dealr
- Topic hub: https://simplefunctions.dev/predictions/election-2026

## License

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