The 2004 US Senate Race in Nevada, a contest between incumbent and new Democratic Senate Leader Harry Reid, and Evangelical Activist Richard Ziser gave Reid a 26% landslide—the largest win of his career.
Winning so large due to locking up Republican support early on, including Governor Kenny Guinn, Reagan Appointee Sig Rogich, and Gaming Executive Terry Lanni.
This, in addition to national republicans abandoning Richard Ziser, and Reid's new control of the Democrat's senate wing allowed him to cruise to reelection.