llinois Gov. Bruce Rauner speaks to students, teachers and community members on the state of Illinois' economy at Richland Community College Tuesday, Jan. 27, 2015, in Decatur Ill. Rauner continued to lay out priorities for his first year in office, telling the audience about a proposal to create so-called ìright to work zonesî was aimed at jump-starting economically depressed areas in the union-friendly state. (AP Photo/Seth Perlman)

CHICAGO — A new study says multimillionaire Bruce Rauner was among the largest donors to political campaigns in the U.S. in last fall's election.

The Center for Public Integrity released an analysis Wednesday of spending on 2014 state-level campaigns.