Lugar dismissed his opponents, although he steered clear of invoking the Tea Party by name.
"Various and sundry groups in our society are trying to illustrate their authority. I understand that they have the right to do that," he said. "I would say this is not a program of ideals for the American people to understand and to cherish and support. Right now our country needs leadership. We need ideas that people can get behind."
Zeroing in on Mourdock, Lugar added, "There has been almost no program coming forth from my opponent about what would happen in agriculture and foreign policy and all the other things that I believe people are interested in."
Lugar made no apologies for his own his efforts to seek consensus and compromise.
"I did, in fact, as chairman of the Agriculture and Foreign Affairs committees, try to [achieve] unanimous consent on many policies, particularly in foreign relations, because I thought it was important that America's face to the rest of the world should have the strongest unanimity as possible."
But he denied shifting to the right in preparation for the campaign. "My voting record has continually been based on what I believe is best for my country and my constituents," he said.
Lugar's prospects have brightened considerably in recent months, thanks to the senator's ample fundraising, his commercials attacking Mourdock and a string of endorsements by high profile Republicans such as Gov. Mitch Daniels, professor Vargus said.
Lugar appears to have weathered the admissions about his residency, including a comment to reporters that he wasn't sure what address was listed on his Indiana driver's license, Vargus added.
The issue lost some potency when the Indiana Election Commission voted 4-0 in February that Lugar should be considered an Indiana resident for the purposes of the election. The vote came after the state attorney general ruled that elected officials who move out of the state for their jobs do not give up their Indiana residency.
"Initially, people thought Lugar faced a pretty serious challenge. … Most people would now say, 'strong advantage Lugar,'" Vargus said.
One wild card is that the Senate primary and Indiana's presidential primary will be held on the same day. If the Republican race for president is not decided by then, and large numbers of evangelical and Tea Party conservatives turn out to vote, Lugar could face an uncomfortably tight race.
"A lot can happen between now and May," Vargus said.