Washington (CNN) -- Democratic Sen. Mark Warner of Virginia on Sunday classified Indiana Republican Senate candidate Richard Mourdock's views on bipartisanship as "wacky."
Appearing on CNN's "State of the Union" beside Republican Sen. Dick Lugar, who lost his party's primary to Mourdock in May, Warner warned of the GOP candidate's ideas.
"I think what Mr. Mourdock said is wacky," Warner told CNN Chief Political Correspondent Candy Crowley. "I don't know what Constitution he wants to defend."
Warner's criticism came in response to a recent Mourdock interview during which he said that "bipartisanship ought to consist of Democrats coming to the Republican point of view."
Mourdock, Indiana's treasurer, beat Lugar, the six-term senator known for his work across the aisle, on a fiscally conservative anti-compromise platform.
Doubling down, Warner said that finding common ground in Congress will be the only way to tackle the debt, taxes and entitlement reform, all of which he said are necessary to right the country's fiscal course.
"The notion that this election is going to be so overwhelmingly for one side or the other, that there's going to be a clear picture and one party's, you know, going to be able to rule the roost, I just don't see that happening," Warner said.
Similarly, Lugar said it would be a mistake to postpone larger discussions until after the election and suggested that the conversations begin now, perhaps surrounding previous plans submitted by the Simpson-Bowles Commission or the Gang of Six.
Congress will need to address the growing deficit and debt ceiling by year's end to stave off dramatic mandatory reductions in spending, among other cuts, agreed upon by both parties as part of last year's debt-ceiling deal.
If compromise could begin now, Lugar said, "I think the American people would be more relieved, and their thoughts about the Congress certainly would be much better."