(CBS News) Sen. Richard Lugar - the longest-serving senator in Indiana history - has lost his Republican Senate primary on Tuesday to state Treasurer Richard Mourdock.
The 80-year-old senator congratulated Mourdock in brief remarks to supporters Tuesday night and said he hoped his primary rival would win in November.
Lugar's exit from the Senate could contribute to the further polarization of an already bitterly-divided Congress.
Lugar has served in the Senate since 1976. The top Republican on the Senate Foreign Relations Committee, he is known for his extensive work on crafting bipartisan foreign policy, which has included reaching across the aisle to pass legislation with Democrat Sam Nunn to disarm nuclear warheads in the former Soviet Union. Lugar's willingness to work with Democrats made him a target: Mourdock ran ads showing President Obama discussing reaching out to Lugar as evidence that the six-term senator should be defeated.