Lamar Alexander Lamar Alexander

NASHVILLE -- The degree to which conservative groups play an outsized role in Republican primary politics is on display in Tennessee, where Joe Carr is running an upstart bid to try to knock off Sen. Lamar Alexander, an establishment legend.

Carr is a state representative who bills himself as a “principled conservative” opposed to many of the bipartisan votes Alexander has cast. In an hourlong interview last month, Carr explained that one of his three goals in the next six months is to prove his potential to the constellation of conservative groups that, so far, have not rallied behind his challenge.

He has never spent more than $125,000 in a campaign before, and so far he’s raised just $325,000 for this race, a sum that is dwarfed by the more than $2.8 million held by Alexander as of Sept. 30. His best chance, Carr said, is to impress groups such as the Senate Conservatives Fund and Club for Growth, who have been the difference makers in other upstart challenges by tea party figures against GOP establishment types.

“For us to be able to have an opportunity to get that money in play, so we can be competitive, we have to raise our own money. … It’s our intention to raise as much money as we can to prove to the outside groups across the country that this is a race of national interest,” Carr said in downtown Nashville.

After making the rounds in Washington, Carr offered a glimpse into what it is like to court those conservative groups. “We have talked to several conservative groups and we’re hearing that there is as much or more than $5 million in different PAC money that may be available,” the challenger said.

So far those groups haven’t tilted Carr’s way, nor have they rejected his candidacy. Aides to SCF declined comment, and Barney Keller of the Club for Growth added: “We’re watching the race.”

For all the talk of grassroots campaigns, the financial engines of tea party insurgents are almost entirely based in Washington. The leading anti-Alexander group in Tennessee ended Sept. 30 with just $25 in its account – yes, $25 – after raising less than $20,000 for the first nine months of 2013.

In his Washington meetings, the first thing that the arch conservative leaders wanted from Carr was for him to meet their “litmus test” in demonstrating his right flank credentials.

“Prove it. You make the case that you are who you say you are,” he said, adding that the groups inform the candidates they will conduct their own research into the candidate’s past to determine if they believe him or not. They also want to see a track record of being an inspiring stump speaker, something that was very much the case with Sens. Marco Rubio (R-Fla.) and Ted Cruz (R-Texas), both of whom overcame establishment figures.

Then the conversations turns toward finances, when they lay out the likely outside independent expenditures if a challenger is deemed to have a legitimate chance of knocking off an entrenched incumbent like Alexander. That’s where the $5 million figure came from, Carr said, recalling the conversation: “Based on our past experience, in a race like this, if we were to show interest, you know, this is what it could potentially look like, and I would never know the commitment until after the fact.”

Any knowledge of the actual commitment would cross into coordination between a candidate and an outside group, which would violate federal election laws. “It’s a conversation, it’s never a commitment. Because that would be a violation of law,” Carr said.

Ultimately, the conservative groups say what they expect if they help a challenger win, because they view the challenger as an investment into implementing their conservative policy.

“That’s the key word here, invest, because there is an ROI that they’re looking for:  a return on investment,” Carr said. “And the return on their investment that they’re looking for is this: We want somebody who is reliable based on the things they said that they would do. That would reflect that on their votes in Congress.”

Without that investment so far, Carr has focused his first round of attacks against Alexander’s behind-the-scenes work in helping reopen the government and raise the debt ceiling.

He’s not nearly as polished as Rubio and Cruz were by the time they entered their respective primary bids, and his knowledge of foreign policy may leave some large donors unimpressed. His biggest critique of the Bush White House’s foreign policy was using military force against Iraq (which began in March 2003) before Afghanistan (which actually began in October 2001).

“We went to Iraq first and then Afghanistan, if you remember. At least in a forceable way. I thought the order in which we dealt with the terrorist threat in Afghanistan and Iraq was out of order. We should have done Afghanistan first,” he said.

Still, the history lesson Carr cares about now – and the one he hopes that outside groups embrace – is turning around Alexander’s use of the metaphor of Davy Crockett and Sam Houston.

“There wouldn’t be a Sam Houston or a republic of Texas had it not been for the 36 Tennesseans who died at the Alamo,” Carr said, rejecting Alexander’s call for Republicans to use Houston’s retreat to higher ground as better strategic thinking. “They had a chance to leave, they did have a chance to leave. But they said no, because what we’re fighting for is worth our lives. If it hadn’t been for the battle cry, remember the Alamo, I doubt Sam Houston and the rest of the Tennessee patriots in Texas would have had the opportunity to save Texas.”