Lugar Loses Primary Challenge in Indiana INDIANAPOLIS - Richard G. Lugar, one of the United States Senate's longest-serving members, a collegial moderate who personified a gentler political era, was turned out of office Tuesday, ending a career that had spanned the terms of half a dozen presidents and had seen broad shifts in the culture of Washington. Mr. Lugar, a six-term senator who had won most of his recent elections with more than 60 percent of the vote, lost a hard-fought Republican primary to Richard E. Mourdock, the Indiana state treasurer. Mr. Mourdock's campaign was fueled by Tea Party groups and national conservative organizations that deemed Mr. Lugar too willing to compromise, and poured millions of dollars into the campaign to defeat him. Mr. Lugar, 80, had not faced a challenge from within his own party since his first election to the Senate in 1976. Mr. Lugar's defeat continued to hollow out the middle of the Senate, and seemed to serve as a caution to other moderates, on both sides of the aisle, known for trying to work with their colleagues. In February, Senator Olympia J. Snowe of Maine, a moderate Republican, decided not to run for re-election, citing polarization in Washington. Senators Kent Conrad of North Dakota, a Democratic fiscal centrist, and Jim Webb, a moderate Democrat from Virginia, are both retiring. Two other moderate Democrats, Claire McCaskill of Missouri and Jon Tester of Montana, face tough re-election races. Tea Party organizers and conservative leaders held the outcome as evidence of a broader, national demand for Republicans with unshakable stances on fiscal reform and conservative values, as well as a proof of the continuing power of the Tea Party movement. "Richard Mourdock's victory truly sends a message to the liberals in the Republican Party," Chris Chocola, president of the Club for Growth, said. Voters are rejecting the policies that led to record debt and diminished economic freedom, and they will continue to be rejected in elections throughout America. For a number of Mr. Lugar's supporters, the results were a sorry arc - not just for a man who had served for 36 years in Washington and as mayor of Indianapolis before that, but for a larger notion of working across party lines in Washington. Still, some Democrats, both here and in Washington, eager to hold onto the Senate, seemed buoyed by the results here. With Mr. Lugar's defeat, they see the glimmer of an opportunity to claim a Senate seat that the party had considered out of reach as long as Mr. Lugar was in the running. The Democratic candidate, Representative Joe Donnelly, is thought to have better chance with independents and moderate Republicans in November against Mr. Mourdock. Almost immediately, Democrats began emphasizing Mr. Mourdock's conservative views. Dan Parker, chairman of the Indiana Democratic Party, issued a statement that read, in part, "Hoosiers deserve real leadership that will reach across the aisle in Richard Lugar's successor, not Richard Mourdock's Tea Party extremism." For months, the campaign here had been intense, expensive and, by Indiana standards, mean. Outside groups including the Club for Growth, the National Rifle Association and FreedomWorks, a group that has helped build the Tea Party movement around the country, had viewed Mr. Lugar as a ripe and overdue target, and poured millions of dollars for advertising and other aid into the race. Mr. Lugar is the ranking Republican on the Senate Foreign Relations Committee and may be best known for his 1990s effort, along with Sam Nunn, a Georgia Democrat, for a disarmament program in the former Soviet Union. He was criticized throughout the campaign for what critics described as his tendency to cooperate with Democrats, including President Obama. He shifted to the right in 2011, after the threat to his re-election became clear. Mr. Mourdock, meanwhile, has said that bipartisanship has led the nation to the brink of bankruptcy, and that the nation's current circumstances call for a time of confrontation, not collegiality. Some of Mr. Lugar's critics accused him of being Mr. Obama's closest Republican friend - a claim Mr. Lugar scoffed at, but also took questions about all the way up until Tuesday afternoon. They also railed against positions he took at various times in favor of Mr. Obama's Supreme Court nominees, the Dream Act, the bank bailout, the New Start nuclear arms control treaty, and more. Mr. Lugar's supporters defended his choices over the years, and argued that his efforts to work across party lines had not diminished his generally conservative views for less government spending, a balanced budget amendment, and fewer rules that harm businesses. For his part, Mr. Lugar, who raced between polling places in a flag-covered tie until the final hours of voting, sounded unbowed on Tuesday afternoon, arguing that most Americans are fed up with partisanship, and saying that his race had evolved into a "playground" for outside interest groups. If it felt peculiar to be entering Election Day as an underdog - Democrats did not even field an opponent six years ago, Mr. Lugar did not show it. "This morning, I woke up after a good night's sleep, just as before, ready with vim and vigor to make certain that we do the Lord's fight today and we're going to do the best we can," he said, before heading to the next stop. But for some here, Mr. Lugar's troubles also reached beyond questions of partisan loyalty. He was required this year to change his voter registration to the farm his family has owned for years rather than the Indianapolis house he sold in 1977 - an episode that underscored how long he had been in Washington and, in the view of even some local, establishment Republicans here, how tenuous his ties now seemed to Indiana. "Everybody's time comes," said Ed Budd, who described himself as a Tea Partier and was handing out Mourdock leaflets outside a polling place in Fairland on Tuesday when Mr. Lugar walked up looking, in Mr. Budd's words, "diminished some" from the familiar image he had seen on television for so many years. Through the day, voters for and against Mr. Lugar confided quietly that they felt discomfort and sadness as they watched the unfolding scene. "This is all really painful to watch," said Larry MacIntyre, a supporter of Mr. Lugar's. Carl Hulse and Jennifer Steinhauer contributed reporting from Washington.