Reilly Neill leads the Democratic primary for Montana’s U.S. Senate seat on June 2, 2026, as traders assign her an 86.5 percent implied probability. Her advantage stems from prior service in the state legislature, early announcement immediately after the 2024 election, and a sustained statewide grassroots effort of roundtables that has built broader name recognition than rivals. Neill also maintains the only campaign with fundraising above six figures, enabling mail and digital outreach while Alani Bankhead, Michael Black Wolf, Michael Hummert, and Kathleen McLaughlin operate with far smaller budgets and lower visibility. Recent independent expenditures opposing Neill have not altered the market’s assessment of her front-runner status ahead of the primary.