Brian Breslin will not seek re-election this year as a Michigan State University trustee.
Sarah Anderson, spokeswoman for the Michigan Republican Party, says Breslin has informed party officials.
Voters choose candidates who are nominated by political parties.
Breslin is chairman of the MSU Board of Trustees.
He has expressed support for President Lou Anna Simon during the controversy over Larry Nassar, who sexually assaulted girls while he was an MSU sports doctor.
Trustees on Friday asked Attorney General Bill Schuette to investigate how MSU handled allegations against Nassar.
Some victims say they were ignored for years.
The 66-year-old Breslin is son of the late Jack Breslin, who was an MSU administrator during decades of campus growth.
The basketball arena is named for Breslin.
