Incumbent Russ Fulcher secured the Republican nomination for Idaho’s 1st congressional district with 78% in the May 2026 primary, while Democrat Kaylee Peterson advanced with 87% on her third attempt for the seat. The district’s consistent Republican performance, including Fulcher’s 71% general-election margin in 2024, underpins trader consensus that heavily favors the incumbent. July 2026 polling showed Fulcher leading Peterson by double digits in a race rated Solid or Safe Republican by major forecasters. With the November 3 general election approaching and no major late-cycle shifts reported, the outcome remains anchored in the district’s partisan composition and Fulcher’s established position. Low-probability disruptions such as a significant scandal, health event, or unusually strong independent performance by Sarah Zabel could alter the result.