Pronóstico: Maine Democratic Senate nominee on July 27?

Platform comparison

Market context

Graham Platner has suspended his campaign for Maine’s Democratic Senate nomination, clearing the way for the party to select a replacement before the July 27 deadline. This withdrawal, confirmed in a video statement on 8 July, follows a sexual assault allegation from 2021 that Platner denies but which has eroded support among key allies [1][2]. The Maine Democratic Party has already voted to hold a nominating convention to choose a new candidate if Platner steps aside, with Charlie Dingman, the party chair, playing a central role in the process [1][6].

Historically, such late-stage nominee replacements in high-stakes Senate races are rare but not unprecedented; the 2018 Florida Senate race saw a similar scenario when a candidate withdrew after primary, prompting a swift party convention. In those cases, the market’s initial low probability (here, 1% YES) often reflects uncertainty about who will emerge, not the likelihood of replacement itself. Conditional tokens on Polymarket, settled in USDC on Polygon, price this contract today based on the apparent nominee status rather than the abstract event, meaning traders are betting on whether Dingman or another figure will be formally announced as the new nominee by 27 July [5][7].

Traders should monitor official announcements from the Maine Democratic Party, particularly any dates for the convention and statements from Dingman, as well as the timeline for Platner’s formal withdrawal before the 13 July deadline [1][4]. Recent reports from CNN and Politico confirm that the party is actively preparing for a replacement, with several Democrats already expressing interest in the race [1][5]. The settlement window ends 27 July at 23:59 UTC, so any delay in the convention or nomination could shift the market’s implied probability significantly [7].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Pronóstico: Maine Democratic Senate nominee on July 27? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Polymarket Qué Es. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

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.