Sen. Herb Kohl (D-WI), chairman of the Senate Special Committee on Aging for the last four years, announced his retirement Friday.

Kohl was first elected to the Senate in 1988. As the Aging Committee chairman, he has played an active roll in long-term care issues, notably pushing for employee background check legislation, among others. Most recently, Kohl put a hold on the nomination of Michelle Leonhart to head the U.S. Drug Enforcement Agency until the DEA and Department of Justice came up with a solution to a policy that kept nursing home patients from receiving pain medication in a timely manner. Kohl worked with LeadingAge and the American Healthcare Association on legislation that would allow nursing home nurses to act as agents of doctors to call in controlled substances, including Schedule II drugs, to pharmacies.
 
The owner of the Milwaukee Bucks, the 76-year-old Kohl is the sixth Democrat to decide not to run for re-election in 2012, USA Today reported. His announcement has set off more speculation over which party would win control of the Senate in the next election. Among possible candidates for Kohl’s seat are House Reps. Paul Ryan (R), Ron Kind (D), Tammy Baldwin (D) and Steve Kagen (D), the Washington Post reported.