In the 2000 election, Niehaus defeated Melvin Dean and Scott Boone to win the Republican nomination with 46% of the vote.

Midway through 2003, Niehaus and Jean Schmidt stated their intentions to run to succeed Senate President Doug White in 2004.

The campaign prompted complaints over fund-raising tactics and featured testy television spots centered on disputes over tax votes.

The Ohio Taxpayers Association launched a $100,000 TV "issue ad" campaign that labeled Mr. Niehaus a tax-hiker.

On opening day of that assembly, Niehaus set a tone for bipartisanship, stating "I want to assure the Senate that this will be a deliberative body where all voices will be heard.