Mark Lamb’s Republican victory in the open AZ-05 seat produced a final margin of approximately 3.4 points after nearly complete vote tabulation. Traders assign 98.5% probability to the Republican 0-5% outcome because official counts from Maricopa and Pinal counties confirmed the narrow win, consistent with the district’s recent partisan lean and the absence of major unresolved ballots. Early Democratic leads on election night narrowed as additional votes were reported, locking in the result by November 6. Remaining scenarios that could alter the recorded margin include formal certification disputes or successful legal challenges, though both appear improbable given the size of the lead and standard Arizona procedures.