 He then faced Indiana State Treasurer Richard Mourdock who had defeated 36-year incumbent Richard Lugar in the Republican primary.On November 6, 2012, Donnelly defeated Mourdock in the general election with 50% of the vote to Mourdock's 44%; Mourdock's loss was attributed by some to his controversial comments about sexual assault.In 2018, Donnelly ran for reelection to a second term, but was defeated by former Republican state representative Mike Braun.