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With 80 percent of the precinct reporting, Mourdock topped Lugar, 60 percent to 40 percent, said the Washington Post.

In recent weeks, Lugar faced backlash by conservatives and Mourdock for his stance on issues including citizenship for some illegal immigrants and backing President Obama's Supreme Court nominees, said the LA Times.  Lugar's crossover with the Obama Administration ruffled feathers with Conservatives both in and out of the state.

Lugar has a long history with straddling party lines in order to compromise on important issues.  Foreign policy issues defined his career, some of his most notable achievements including limiting the congressional authorization for war and teaming up with Obama to win Senate approval of a Russian arms reduction pact, said Reuters.

Despite praising Mourdock in his concession speech as "a truly great public servant," Lugar's written statement pegged Mourdock as occupying an "unrelenting partisan mind-set" and warning that "he will achieve little as legislator" unless he budges on his strict conservatism, said USA Today.

Democrats hope a loss for Lugar will bring them one step closer to a Senate seat.  The Washington Post reports the reputation of 2012 Democratic nominee Rep. Joe Donnelly as a centrist will fare well against Mourdock's extremist stance. 

Reach Amanda Martinez here