Sen. Richard Lugar (R-Ind.) is trailing his conservative primary challenger in a new poll commissioned by the fiscally-conservative Club for Growth, a group that has attacked him in the past.
The incumbent senator, who’s facing one of the toughest challenges of his career, is down by 2 points with one-third of GOP primary voters undecided.
Indiana state treasurer Richard Mourdock has the backing of 34 percent of Republican primary voters while Lugar gets 32 percent and 34 percent are undecided, the poll found.
The Club for Growth, which has made noises about backing Mourdock in the primary, did not release the full poll or give all the details for how it identified Republican primary voters, which casts some doubt on its results. The group has run ads attacking Lugar’s record and warning him against voting for an increase to the debt ceiling, and Lugar’s campaign questioned the poll’s methodology.
“The data released by the Club for Growth does not resemble anything we are seeing,” said Lugar Political Director David Willkie. “Before commenting on a purely publicity driven poll commissioned by an outside group that has spent hundreds of thousands of dollars against us, we need to know much more about the methodology.”
The Club for Growth refused to release the full poll questionnaire or results but the group’s spokesman pushed hard against the Lugar campaign’s suggestion that it was a push poll designed to make Lugar look beatable. “It’s a straight ballot test,” said Club for Growth spokesman Barney Keller. “I’m sure Sen. Lugar and his allies are going to be completely disappointed by this poll and will say and do anything to discredit it.”
The senator has been a leading target for the conservative Tea Party movement this cycle and these numbers indicate he is in a tough spot despite reassurances from Lugar’s campaign that the senator will breeze by Mourdock in the primary.
"An incumbent who sits at 32 percent in his own party’s primary, and trails a much less known challenger, is in a world of trouble," said Club for Growth President Chris Chocola in a statement. "Senator Lugar is a very decent man, but it’s clear from the poll that after 35 years, Hoosier Republicans are eager for a more conservative alternative."
Lugar, the most senior Republican in the Senate, has not faced any real competition in decades. He did not face major-party opposition in 2006, and the last time he was held to under 60 percent of the vote was in 1982.
But he angered some conservatives by voting for the Troubled Asset Relief Program (TARP), which has been characterized as a Wall Street bailout, and voting to confirm both of President Obama's Supreme Court nominations. Lugar has also backed the DREAM Act, a measure favored by the administration which would give some illegal immigrants brought here as children a path to citizenship.
Mourdock has worked to capitalize on Lugar’s positions as well as the perception the senator is a Washington insider.
In an interview with The Hill earlier this month, Mourdock attacked Lugar for not being conservative enough on economic issues and for being too much of a foreign policy wonk.
"People in Indiana want to see fiscal controls, they want to see someone who’s with them regularly back there, not just someone sitting in Washington, D.C. thinking about the lofty issues of foreign affairs," he said. "People in Indiana care less about democracy in the Middle East than they care about Hoosier jobs moving to China."
The poll was conducted by the Republican firm Basswood Research from July 23-24. The sample contained 500 likely Republican primary voters, with a margin of error of plus or minus 4.4 percent.

This post was updated at 3:20pm.