AUDIE CORNISH, HOST:
Now, a story about big political spending by outside groups not in the presidential campaign, but in a Senate race. Republican Richard Lugar of Indiana is facing a primary challenge.
And one group that's supporting him is causing some confusion, as we hear from NPR's Tamara Keith.
TAMARA KEITH, BYLINE: YG Network describes itself as supporting center-right policies and the policy-makers who fight for those policies. YG is short for Young Guns, a brand created in part by House Majority Leader Eric Cantor. The YG Network and two similarly named sister organizations were started late last year by former Cantor aids.
And, in their short existence, these YG groups have generated their share of controversy. Most recently, it came in the form of a mailer sent to Indiana voters. William Jacobson runs the Conservative Legal Insurrection blog and wrote about the mailer.
WILLIAM JACOBSON: A reader actually emailed me a copy that he received, which he was quite upset about.
KEITH: Last week, the YG Network spent more than $200,000 on mailers in support of Indiana Senator Dick Lugar, who's facing a tough primary challenge from the state treasurer. What got people upset is what the mailer said. In not so many words, it encouraged Democrats and Independents to vote in the Republican primary and support Lugar. Jacobson and a lot of other conservatives don't like the message that sends.
JACOBSON: You're basically saying, we don't care what the Republican voters think, what we care is that Richard Lugar gets the nomination. And I think that's what sits poorly with a lot of people.
KEITH: And, generally, encouraging people from the other party to try and sway your party's primary is a big political no-no. Mitt Romney was none too happy when Rick Santorum's campaign did something similar in the lead-up to the Michigan primary. This was Romney on Fox News channel.
MITT ROMNEY: It's confusing people. It's a new low in this campaign.
KEITH: When it comes to the YG Network mailer in the Senate race, former GOP congressman from Indiana, Mark Souder, is baffled.
REPRESENTATIVE MARK SOUDER: Why a Young Guns movement to try to make sure we have future leadership that's strong and advocates consistent conservative principles would join in with Lugar is just strange.
KEITH: Not least because, at 80 years old, Lugar is one of the longest serving members of the Senate and could hardly be described as a young gun.
This isn't the first time the YG groups have created a flap within a Republican primary. The YG Action Fund, a superPAC, spent $52,000 on radio ads to support Adam Kinzinger in an incumbent versus incumbent primary in Illinois this year. It worked and 10-term congressman, Don Manzullo, lost. Souder says this caused some unrest.
SOUDER: It was very upsetting to him and many friends of his that they got involved in that primary, but at least you could understand a little. This is much more bizarre.
KEITH: For Eric Cantor, the majority leader, these intraparty forays by the YG groups are generating ill will. Virtually every story about this controversial mailer describes the YG Network as a Cantor-affiliated group and those are the charitable ones.
Many conservatives and conservative groups are blaming Cantor directly, including the Club for Growth, which has endorsed the challenger in the Indiana Senate race, Richard Mourdock. Barney Keller is the group's spokesman.
BARNEY KELLER: You know, there's a big difference in what those two candidates stand for and it's just unfortunate that Eric Cantor and the Republican leadership is promoting the more liberal candidate.
KEITH: The club has poured nearly a million and a half dollars into the race. YG Action and YG Network did not respond to repeated requests for comment and Cantor's office stressed that he has nothing to do with the YG superPAC or any other superPAC.
Tamara Keith, NPR News, Washington.