Maine Governor Democratic Primary Winner

Platform comparison

Active sub-markets

Market context

Maine's Democratic Party will hold a gubernatorial primary on 9 June 2026 to select its nominee for the state's top executive office. A YES share represents a bet that a specific candidate wins that primary; a NO share represents a bet against that outcome. The 4% implied probability suggests the market views this particular candidate as a long-shot contender relative to other Democratic hopefuls expected to enter the race.

Maine's recent gubernatorial history offers limited precedent for competitive Democratic primaries. Janet Mills won the governorship in 2018 and secured re-election in 2022 with substantial margins, facing minimal primary opposition either cycle. The state's Democratic establishment has historically coalesced around frontrunners early, reducing multi-candidate primary contests. However, Mills is term-limited and cannot seek a third consecutive term, meaning 2026 will be an open primary—a scenario that typically attracts larger candidate fields and more genuine competitive dynamics than incumbent-defence races.

Traders should monitor candidate announcements beginning in late 2025 and into early 2026, as the field composition will substantially alter probability assessments. Key variables include whether any sitting state legislators or Congress members enter the race, the extent of labour-union and progressive-activist endorsements, and fundraising disclosures filed with Maine's Commission on Governmental Ethics and Election Practices. Mills' own positioning—whether she endorses a successor or remains neutral—will carry significant weight among party delegates and voters. The primary date itself is fixed, eliminating scheduling uncertainty as a resolution factor.

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). The odds column is filled only where we have clean data — that avoids the made-up numbers that get a network demoted when search engines cross-check against the source venue.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

Where can I trade this market with the lowest fees?

On Prediction Market UK, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Prediction Market UK is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

What does it cost to trade on Prediction Market UK?

Zero. Prediction Market UK routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.