Background

Susan Collins is a Republican U.S. Senator from Maine who has served since 1997. She has historically outperformed typical Republican candidates in Maine, positioning herself as a moderate in a state that leans Democratic overall.

A January 2025 political science paper titled "The Electoral Consequences of Ideological Persuasion: Evidence from a Within-Precinct Analysis of U.S. Elections" by Bonica, Rhee, and Studen examines how candidate ideology affects vote share. The paper finds that a standard deviation change in ideological midpoint between candidates results in an average vote share penalty of 0.6 percentage points, with the authors concluding that "gains associated with ideological moderation are relatively modest and likely secondary to turnout effects."

Matthew Yglesias has challenged this paper's conclusions, suggesting that moderates like Susan Collins consistently outperform their state's partisan baseline, contrary to the paper's findings that ideological moderation offers only modest electoral advantages.

Resolution Criteria

This market will resolve to YES if Susan Collins outperforms the Republican partisan baseline in Maine by any margin in the 2026 Senate election, supporting Yglesias's position that moderate candidates like Collins do gain significant electoral advantages from their ideological positioning.

The market will resolve to NO if Susan Collins underperforms relative to the Republican partisan baseline in Maine in the 2026 Senate election.

The market will resolve to N/A if Susan Collins does not run for re-election in 2026.

The partisan baseline will be calculated by averaging Republican performance across other major statewide races in Maine during the 2024 and 2026 election cycles (including presidential, gubernatorial, and other federal races as applicable)