But according to The Tennessean, Kookogey, a conservative activist and former local Republican Party chairman, has withdrawn himself from the candidate vetting process currently being conducted by organizers of a political action committee (PAC) created to find a primary challenger for the senator.

Kookogey emailed the organizer of a series of candidate vetting forums to withdraw his name to avoid confusion.

“Thank you for inviting and allowing me to participate in the Beat Lamar forum yesterday in Nashville,” Kookogey told Michael Patrick LeahyPatrick Joseph LeahyMcConnell sets 'minibus' strategy for 2019 spending Dem senator mocks Pruitt over alleged security threats: 'Nobody even knows who you are' Pruitt tells senators: ‘I share your concerns about some of these decisions’ MORE, a co-founder of the Beat Lamar PAC.

He added: “As an unannounced candidate, however, I have decided to withdraw from the remainder of the scheduled events, lest my attendance confuse your process."

Kookogey had not yet made his run official, but he's known to be looking closely at a run. This new development would seem to press pause on the likely candidacy of a local activist who has held strong appeal for conservatives.

He's gained attention within the movement for his activism against the IRS, speaking at a House hearing on the extra scrutiny his 501(c)(4) group received from the agency.

Drew Ryun, head of the conservative Madison Project, told The Hill that the group had met with Kookogey and found him to be "a formidable candidate."

“Kevin Kookogey met with us several months ago, and we were impressed with his personal fight against the IRS in helping expose their scandal to target conservative groups.  His sharp conservative intellect and fighting spirit make him a formidable candidate.  We'll be monitoring any budding primary challenger very closely over the next few months to ensure that 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 is not the Republican nominee for Senate next year," he said.

Conservative groups have put Alexander in their sights for 2014, and he's already been the target of ads from the Senate Conservatives Fund for refusing to sign onto a conservative-led movement pledging to shut down the government if ObamaCare isn't defunded.

The senator already has one challenger in state Rep. Joe Carr (R), who dropped out of a challenge to Rep. Scott DesJarlais (R-Tenn.) late last month to instead pursue the GOP nomination for Senate.

Carr's candidacy has been met with skepticism from some conservative groups, however, who still say they're looking for a candidate to take down the incumbent. Ryun's comments would seem to indicate a warmer reception for Kookogey.

But Alexander has been preparing for some time for a potential challenge, and last week went on air with an ad defending his record on ObamaCare. His campaign also released polling that shows him leading every potential primary challenger by substantial double-digit margins.

—This piece was updated at 11:24 a.m. to clarify Kookogey's position on the race.