In the final, frenzied days before an election, most U.S. Senate campaigns jam the calendar with voter rallies and message events to encourage as many supporters to go to the polls as possible.

But in the three weeks leading up to Thursday’s primary in Tennessee, state Rep. Joe Carr’s campaign is sponsoring no rallies and holding no message events. Instead, the leading challenger to Sen. Lamar Alexander is crisscrossing the state to attend local GOP meetings and headline nine “Restore America—Joe Carr for U.S. Senate” rallies.

The rallies feature all of the must-haves for a campaign event, including streamers, “Beat Lamar” yard signs, fresh-faced staff in matching “Beat Lamar” T-shirts and, of course, the candidate himself. The largest to-date featured radio host Laura Ingraham in Nashville, rallying 800 conservatives to go the polls for Carr and “Beat Lamar.”

But the events are not a part of the Carr for Senate campaign, nor does his campaign pay for them. Instead, they are sponsored by the Real Conservatives National Committee, a Super PAC run by Tea Party veteran and grassroots ace Michael Patrick Leahy that created “Beat Lamar” to choose and then rally behind a conservative challenger to Alexander.

Leahy’s goal, he says, is to be the “the conservative ground game specialists.” Unlike traditional Super PACs that typically operate at arm’s length from campaigns by focusing on ad buys, the “Beat Lamar” effort has often put the candidate at the center of its work.

In addition to the rallies, Beat Lamar has paid a team of more than 40 canvassers to knock on more than 80,000 doors on Carr’s behalf, to attend Alexander campaign events with “Beat Lamar” signs, and to staff the Beat Lamar events that Carr attends.

The arrangement is unorthodox enough that it could revolutionize the role that Super PACs play in campaigns. But it also dances on the edge of campaign finance law, which allows candidates to appear at Super PAC events, but prohibits any coordination of strategy or resources between a Super PAC and a campaign.

Larry Noble, the former General Counsel to the FEC, called the series of “Beat Lamar” rallies in the absence of anything put on by the Carr campaign “very odd.”

“There is a strong argument here that [the RCNC] is not running a shadow campaign or even a parallel campaign, but they are running a campaign with the candidate,” Noble said. “If these are events that are all about him and all about electing him, then there are serious issues about potentially crossing the line.”

But in an interview with The Daily Beast, Leahy said the two efforts have no crossover.

“We don’t coordinate with the campaign, but we have endorsed Joe and we invite him to attend the events,” Leahy told The Daily Beast. “We originally set up the events as debates on immigration and invited Lamar and Joe. Joe accepted immediately. Lamar never responded.”

I spoke with Carr after a “Beat Lamar” rally for about 100 at a motel outside of Chattanooga, where we talked about his record in the Tennessee state house writing some of the toughest immigration laws in the country, including a mandatory e-verify system for employers and a prohibition on sanctuary cities. He also spoke, unprompted, about his campaign’s finances.

“We've run a very different campaign than all the other campaigns before us. We have not received the outside financial help that other campaigns have received,” Carr said, a reference to the cold shoulder his campaign has gotten from the Senate Conservatives Fund, the Club for Growth and other Washington-based conservative money groups.

“We’ve raised almost $1.3 million, of that we’ve received $16,000 in PAC money. That’s 1 percent. I mention that because I’m very proud of it,” Carr said, noting that $5,000 of the PAC money came from Sarah Palin’s PAC after she endorsed him.

But left unsaid was the support that Carr has gotten indirectly both from “Beat Lamar,” which has raised about $260,000 and spent nearly all of it on a ground game for Carr, and Citizens 4 Ethics in Government, a second Super PAC that has spent more than $250,000 in ads against Alexander in the campaign’s final week, and about $30,000 supporting Carr.

In addition to supporting Carr for Senate, the common thread linking the Carr campaign, “Beat Lamar,” and Citizens 4 Ethics in Government is Andy Miller, a conservative venture capitalist based in Nashville who has maxed out to Carr’s campaign with $5,200, and is the largest individual donor to both Super PACS, having given $52,500 to the RCNC and $120,000 to Citizens 4 Ethics in Government.

Leahy calls Miller “a donor and a good guy,” but other Tennessee Republicans have less kind words for him. “He’s the dark overlord of right-wing candidates in Tennessee,” one GOP operative said.

As one of Carr’s largest supporters, Miller made news this year when the Carr campaign made a $200,000 loan to one of Miller’s companies, an arrangement the Carr campaign said it cleared first with the Federal Election Commission. Miller was in the news again last month when an Alaskan blogger uncovered documents that showed Miller and Todd Palin as co-investors in an Alaska hospitality company.

But even with the outside help from Miller and others, Carr won’t come close to matching the Alexander campaign’s resources, nearly $7 million raised so far, some of which has paid for a 32-city bus tour across the state. The luxury bus has occasionally been met by sign-wielding “Bear Lamar” staffers, several of whom described Carr as “an average Joe” and an “inspiration.”

Carr himself is a natural challenger for the times, a home-schooling, gun-owning, white-haired grandfather with more than a bit of a contrarian streak. For Tea Partiers looking for red meat, Carr offers a record of real-world, far-right legislating, without Chris McDaniel’s wild-eye conspiracy theories. He points to Mike Lee of Utah as the type of senator he’d like to be--conservative, consistent, analytical.

Had Carr run four years ago, like Lee, he might have been able to better harness the white-hot Tea Party anger than he has in 2014, when Republican leaders in Washington are struggling to live up to the hope activists had for them in 2010.

But Carr is still making his pitch to Tennesseans to unseat the plaid-clad, courtly senior senator, whom Carr argues hasn’t got much to show for 12 years in the Senate.

“There’s nothing wrong with Lamar. I like him,” Carr said before he left the “Beat Lamar” rally in Chattanooga. “But he hasn’t done anything. That’s the point.”