Nelson was thought to be in danger of losing his seat in 2006, as it was thought his successor as governor, Mike Johanns, was almost certain to run against him; that speculation ended when Johanns was appointed U.S. Secretary of Agriculture. With Johanns's move to Washington, few high-profile Republicans stepped up to run against Nelson, as the state party focused its attention on the governor's race. The Republican nomination was won by Pete Ricketts, a former TD Ameritrade executive.