State Senator Tim Cullen of Janesville is calling it quits. The Democrat announced Thursday morning he will not seek another term in the State Senate. Cullen says he can make a bigger difference in the community as a private citizen, than he can in the ugly political environment seen now in Wisconsin government. Cullen says he'll be forever grateful to the people of the 15th Senate District for placing their trust in him many years ago, and again in 2010. He says he went back to public office to try to make a difference in the lives of people, but serving in the minority significantly limited his ability to help Wisconsin in ways he believed would benefit the state. Cullen intends to focus his efforts on two foundations he started before he made his return to the State Senate. He also plans on getting involved with several non-profits, and is considering starting another foundation related to education.