Mark Lamb leads the AZ-05 House race in trader consensus at 61 percent implied probability due to the district's consistent Republican tilt, including a 20-point GOP margin in the prior cycle, combined with his strong primary performance, substantial fundraising edge of roughly $1.8 million to $376,000, and endorsement from former President Trump. The open seat left by Andy Biggs, who is pursuing the governorship, has allowed Lamb's background as former Pinal County sheriff and focus on border security to resonate with the electorate in Maricopa and Pinal counties. Elizabeth Lee's campaign emphasizes healthcare and education but faces structural headwinds in a district where early voting patterns mirror prior Republican-leaning cycles. Models from multiple forecasters project Lamb ahead by 9–10 points heading into the November 3 election, with limited public polling leaving fundraising and partisan composition as primary signals for traders assessing the outcome.