The 34-year-old Marine veteran prevailed in a six-way GOP primary that included an orthopedic surgeon, a clinical physiologist and political event organizer whose wide-ranging resume included stints as an autoworker, model and real estate agent.
The first-term treasurer was heavily favored to win.
He has already raised $4 million in his bid to unseat Democratic incumbent Sherrod Brown in the fall. Brown is a former congressman and Ohio secretary of state with a progressive following around the state.
Ohio Democrats have lobbed accusations at Mandel all year, including that he has neglected his treasurer duties for his Senate campaign.
Copyright 2012 The Associated Press.
