After serving two terms in the Ohio House of Representatives, Grendell ran for the Ohio Senate in 2004, and won with 59.6% of the vote over Democrat John Hawkins [REF].
In the 129th General Assembly, Grendell was a member of the committees on Agriculture, Environment and Natural Resources; Government Oversight and Reform (as vice chairman); Judiciary-Criminal Justice (as chairman); and State and Local Government and Veteran's Affairs.