"He's achieved many things in the foreign policy arena," said Sen. Dan Coats, R-Ind. "That's one of the essential roles of the Senate. But that's not what's on people's minds today during this time of tough economic times. People are just discounting that."
Mourdock won handily, 60-40 percent.
In a speech on the Senate floor Wednesday, Foreign Relations Committee Chairman John Kerry, D-Mass., said Lugar "refused to allow this march to an orthodoxy about ideology and partisan politics to get in the way of what he thought was the responsibility of a senator and ... the need of the country to have people come together and find the common ground."
Sen. Dick Durbin, D-Ill., said of Lugar's defeat: "It's a sad day on both sides of the aisle."
During his tenure, Lugar has been the point man for presidents on arms control treaties, steering strategic arms reduction pacts to reality for Presidents George H.W. Bush, Bill Clinton and Barack Obama. He backed NATO expansion, insisted that the United States pay its dues to the United Nations and favored aid to the Nicaraguan Contra rebels as he headed the Senate Foreign Relations Committee from 1985-87 and 2003-07.
He ran for president in 1996 on a slogan of "nuclear security and fiscal sanity." It was Lugar, as mayor of Indianapolis in the late 1960s, who steered the city financially and argued against federal programs. That earned him the title of President Richard Nixon's favorite mayor.
In August 2005, Lugar and the new senator from Illinois, Barack Obama, traveled to Russia, Ukraine and Azerbaijan to check on the progress of nuclear disarmament. That earned Lugar the title of Obama's favorite Republican, a moniker used against him in the campaign.
In a statement Tuesday, Obama praised Lugar as a man who "comes from a tradition of strong, bipartisan leadership on national security that helped us prevail in the Cold War and sustain American leadership ever since."
Defense Secretary Leon Panetta, at a Washington symposium, called Lugar a "statesman" who "often reached across the aisle to try to find consensus on some of the most challenging issues of our times, and that's what leadership is all about."
Earlier this month, Lugar released the latest scorecard from the Nunn-Lugar cooperative threat reduction program established to help the former Soviet states destroy nuclear, chemical and biological weapons and safeguard the remaining material to keep it from the hands of terrorists. To date, 7,619 strategic nuclear warheads have been deactivated, 902 intercontinental ballistic missiles destroyed, 498 ICBM silos eliminated, 155 bombers destroyed and the list goes on. Ukraine, Kazakhstan and Belarus are nuclear weapon free.
"Richard Lugar's a national hero," said Joe Cirincione, president of the Ploughshares Fund, a group dedicated to disarmament. "If he wasn't there, we would face greater threats today. We're safer because of what he's done."
Lugar's loss, said Cirincione, "does more to weaken our national security than dozen of terrorists threats in the Middle East."
Associated Press broadcast writer Sagar Meghani contributed to this report.
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