Sharp words flew at Monday's senate debate. The three candidates pounded each other over issues ranging from social security and Medicare to taxes and the national debt.
Libertarian Andy Horning said voters should elect him to avoid more of what had just gone on.
"I think you've seen between the two on my right exactly what's going to happen if you vote status quo again," Horning said. "It's always going to be a tug of war, and you're always going to lose."
Mourdock also is fighting his portrayal by Donnelly as a partisan politician. In response to a question, he says he's worked with Democrats to set up a college savings plan for Indiana parents.
Donnelly says he's worked with Republican colleagues on a veterans center in South Bend and to keep Air Force fighter jets in Fort Wayne.
Mourdock and Donnelly also clashed over Social Security and Medicare, with Mourdock denying he had ever said those programs are unconstitutional.
Indiana's Senate battle is one of a handful of tight races that will decide whether Democrats or Republicans control the Senate.
A Rasmussen poll just out Monday showed Mourdock leading Donnelly by five points, the biggest margin any public poll has shown between the candidates in months.