INDIANAPOLIS -- Sen. Richard Lugar says he will not campaign for the man who vanquished him in May's Republican primary.

Lugar told conservative Indiana blogger Abdul Hakim-Shabazz in an interview posted Monday that he would not actively support Republican Senate candidate Richard Mourdock on the campaign trail. The six-term senator had previously left the question unanswered. But he raised eyebrows in July when he introduced Mourdock to Senate Republicans at a weekly lunch.

Mourdock is in a tight race with Democrat Joe Donnelly for Indiana's open Senate seat. Senate Republicans and Democrats are going on air in Indiana Tuesday with new ads and outside groups are spending heavily on both sides.

Polls have shown a surprisingly close race for what would have been a safe Republican seat had Lugar won re-election.

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