Sen. Lugar not planning "active" campaign for Mourdock

(CBS News) In his first interview since he lost his primary earlier this month, Indiana Republican Senator Richard Lugar said he had no plans to campaign for Richard Mourdock, who beat him.

"For the time being, I don't plan an active campaign," Lugar said on "Face the Nation."

The 80-year old lawmaker, known for reaching a landmark post-Cold War agreement on weapons reductions with Russia, has served in the Senate for 36 years. He lost to Tea Party-backed State Treasurer Richard Mourdock by 20 percent during the May 8 primary.

Lugar told host Bob Schieffer that Republican voters in Indiana wrote off the need for bipartisanship.

"A large portion of the Republican Party of Indiana believed, apparently, in the idea of individualism as opposed to community - a sense of compromise or a sense of talking across the aisle," Lugar said.

The senator largely dismissed the critique that he no longer had a residence in Indiana and spent most of his time in Washington or traveling overseas on foreign policy trips. He blamed the money and influence of outside groups, including the National Rifle Association, the Washington-based Tea Party group FreedomWorks, and the anti-tax lobby Club for Growth, for his loss.

"They are able to come in early on with hundreds of thousands and millions of dollars with negative ads, which turned around what usually was an approval that I had from 60 to 70 percent for all of these years, and it went down real fast in the last two or three weeks under that barrage," Lugar said.

The outgoing senator said he hopes Mourdock wins, to help Republicans regain the majority in the Senate, but he has some advice for the Senate candidate, who still faces a Democratic challenger in November.

"I have offered advice to my former opponent... as to trying a way he could be a constructive senator and how he could make any difference whatsoever. I hope he will, in fact, begin to adopt some of those ideas," Lugar said.

Known for his foreign-policy credentials as top Republican on the Foreign Relations committee, Lugar said President Obama "has been very cautious" in regards to Syria. "I think properly so."