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The conservative challenger who ousted longtime Republican Sen. Richard Lugar in the Indiana primary Tuesday is pointing to his victory as a sign the Tea Party is alive and well -- as Democrats pounce on the win to argue the GOP is once again taking an "extremist" turn.

State Treasurer Richard Mourdock crushed Lugar, who has held his seat since 1977, by more than 20 percentage points. The frustration of defeat showed overnight, as Lugar criticized
Mourdock's "unrelenting partisan mindset."

Mourdock, in an interview with Fox News Wednesday morning, said Lugar is "in my thoughts."

"He is a great American, a historic figure," Mourdock said, adding that his margin of victory must be "difficult" for Lugar.

But, he said, "it's time to move forward," and was unapologetic about the hard-charging race he ran and his vision for a strong conservative majority across Washington. In pointing to his win, he rejected the idea that the Tea Party is moving toward irrelevance.

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"If anyone really believed that about the Tea Parties, they were mistaken," Mourdock told Fox News. He cited the "thousands" of Tea Party volunteers and others who helped him in the campaign and said "it got us to the finish line successfully."

Democratic strategists, for their part, have tried hard to keep alive the bogeyman of an "extremist" Tea Party lurking around the election corner. Mourdock's victory served that purpose, and statements flowed at a steady pace late into the night from Democratic groups.

"It's official: the Republican Party is now indistinguishable from the Tea Party," Democratic National Committee Chairman Debbie Wasserman Schultz said in a statement.

Guy Cecil, director of the Democratic Senatorial Campaign Committee, claimed Mourdock's victory improved the Democrats' chances in the fall.

"Tens of thousands of Hoosiers who have voted for Dick Lugar their entire voting lives are going to reject a Tea Party candidate like Richard Mourdock and support an honest, common sense job creator like Joe Donnelly," he said, referring to the Democratic candidate.

Mourdock, who had been criticized as overly partisan by Lugar and others, defended his approach Wednesday. He said he believes bipartisanship should consist of Democrats coming over to the GOP way of thinking.

He said he hopes to help build a Republican majority in the Senate, "and then bipartisanship becomes having Democrats come our way. "

Lugar's defeat makes him the first senator -- and likely the only one -- to lose renomination this year.

Mourdock's supporters cast Lugar as too moderate and out of touch after 35 years in the Senate.  The American Conservative Union gave Lugar a 77 percent "lifetime" rating. Lugar's supporters claimed it hardly constituted a moderate voting record. But Tea Party conservatives argued Mourdock would provide more "purity" and wouldn't bow to compromise with Democrats.

Sens. Orrin Hatch, R-Utah, and John McCain, R-Ariz., avoided situations similar to Lugar's by moving further to the right ideologically. Lugar, however, initially refused to do the same. He didn't run a slew of negative advertisements against his opponent until late in the primary campaign. Even then, some critics said they stood in contrast to his reputation as a statesman.