Sen. Lamar AlexanderAndrew (Lamar) Lamar AlexanderOvernight Health Care — Sponsored by PCMA — Abortion rights group plans M campaign to flip the House Senate health committee to hold hearing on Trump drug pricing plan Overnight Health Care — Sponsored by PCMA — VA reform bill heads to Trump's desk MORE’s (R-Tenn.) primary challenger is convinced he’s the next Dave Brat, the man who orchestrated a stunning upset of House Majority Leader Eric Cantor in his primary last week.

And if state Rep. Joe Carr (R) does pull off a similarly unexpected win over the two-term senator, he said he’ll have Brat to thank for the momentum that gets him there.

“What we have always assumed is that there was going to be a combustible moment in the campaign. We didn’t know when it was going to occur, or how it was going to occur,” he told The Hill last Thursday, during a two-day visit to Washington to meet with national conservative groups and lawmakers he said were newly warming to his bid.

“But we knew that combustible moment, for it to have a relevant and lasting impact on our race, would require us as a campaign to pile as much combustible material on that pile so when that moment came that we could sit there and light that fuse. And that’s what happened Tuesday.”

Like Brat, Carr faces a significant money deficit; he posted $460,000 to Alexander’s $3.1 million in the bank at the end of March. And Carr doesn’t yet have much support from national conservative groups that have proven to be effective in some other races. Also like Brat, Carr isn’t taken particularly seriously by establishment actors in his state and significantly lags the incumbent in polling — by 45 points in the last survey of the race.

But the underdog said that, beginning with Mississippi state Sen. Chris McDaniel’s success in pushing Sen. Thad Cochran (R-Miss.) to a primary runoff two weeks ago, he had seen interest from groups that had otherwise ruled out supporting his candidacy. Alexander, like Cochran, is seen by conservatives as having too liberal a voting record and too willing to work with the establishment on issues.

An aide said Carr raised “tens of thousands of dollars” online in the day after Brat’s win and signed up hundreds of new volunteers for the campaign last week.

When he first jumped into the race, national conservative groups signaled they weren’t interested, noting he had failed to pick up traction in his initial primary challenge to embattled and severely weakened Rep. Scott DesJarlais (R-Tenn.). 

But some signaled this week that the timing of the Tennessee Senate primary — in early August, when most other primaries are off the map and conservative groups will have resources and attention to spend elsewhere — could make it ripe for an upset.

“Once the Mississippi race is settled, we have no doubt that conservative grassroots momentum will bring Senate Primary races like the ones in Tennessee and Kansas to the forefront of the political discussion,” said Citizen United President David Bossie. 

Carr wouldn’t give specifics on which groups were showing renewed interest, but in the past 10 days he’s picked up endorsements from conservative radio host Laura Ingraham — who helped drive Brat to a win — and the Gun Owners of America. 

Last Thursday, he also had plans to meet with Sen. Mike Lee (R-Utah), another conservative star, who doesn’t weigh in on incumbent primaries but has ties to a number of influential conservative groups. To keep that momentum going, he’s launching his first statewide television buy on June 26, just two days after the Mississippi Senate runoff election.

But some of those groups may still find red flags in his record as a state legislator.

In 2009, Carr voted in the statehouse in favor of implementing Common Core education standards, in part to secure the state half a billion dollars in federal funds for education. Common Core is now a toxic issue for conservatives, and Carr said Thursday he “deeply regrets” that vote and made it because he didn’t fully understand the impacts of the policy at the time.

He said if he’s elected he would try to avoid similar mistakes by not being “as complacent as Sen. Alexander in understanding and reading the legislation before I vote on it” — though he admitted lawmakers can’t read every law themselves.

“It’s not physically possible, there aren’t enough hours in the day, but you have to have a staff that understands your priorities” reading through the legislation for you, he said.

But, he added: “I doubt there would ever be mistakes in standing with my principles. There may be some mistakes in standing with issues. Issues and principles are not the same thing.”

“Common Core is an issue; however, it’s evolved into a principle. ... If I had understood that my vote might’ve been different. But it evolved into a principle because Common Core, in the last four years, has changed, how it has been administered, how it has been delivered in the state has evolved,” he said.

Carr also broke with what’s typically considered conservative orthodoxy in pushing to secure stimulus grants to build a science facility for Middle Tennessee State University in 2009.

He defended that effort as an attempt to deliver the Volunteer State its due.

“If they are going to provide that stimulus funding anyway, then the state of Tennessee and MTSU should be able to benefit from that,” he said.

He wouldn’t comment on whether he’d vote for a similar stimulus package in the future, as long as it included funding for Tennessee, but left the door open to it.

“It just depends. I would be extremely unlikely to do so, but again, without knowing the particulars it would be extremely difficult to answer,” he said.

Carr can, however, count his work leading the fight for tough restrictions on illegal immigration as a major asset in the primary. And he believes that simply the anti-incumbent, anti-Washington political atmosphere this cycle will also make him competitive.

“Lamar’s appeal in the state is broad, but very very shallow,” he said of the former governor and Cabinet secretary. “People understand that they like him, but they like him within the context of a grandfather or a great-grandfather.”