The open seat created by retiring Republican incumbent Andy Biggs has produced a competitive general election between Republican Mark Lamb and Democrat Elizabeth Lee in Arizona’s 5th district, where forecasts project a Republican margin near 10 points amid a district PVI around R+10. Limited public polling and reliance on fundamentals such as past presidential results and turnout patterns have kept winner odds near even in trader consensus while concentrating probability on Republican margins of 5-15 points. Recent primary outcomes, fundraising differentials, and the absence of late-breaking events or major endorsements have sustained this positioning, with final-week turnout among independents and suburban voters in Maricopa and Pinal counties the primary variable that could widen or narrow the result before November 3.