Robert Lorge was the Republican candidate for the seat after being the only Republican candidate to file before the filing deadline on July 11, 2006. Despite receiving no money or support from the State or National Republican Republican party he fared better than Republican Senate candidates in New York, Massachusetts, North Dakota, and was the only major party candidate in 2006 able to deliver votes for under $1 in the Post McCain-Feingold Campaign Finance Law era.
Kohl won a majority in every county in the state. Kohl's weakest performance in the state was suburban Washington County, Wisconsin, which Kohl won with just 49.6%. Kohl's strongest performance was in rural Menominee County, where he won with over 90% of the vote. Vogeler's best performance was in Dane County, where she came in third place with over 5%, a county where Lorge had his second weakest performance.