Republican Brian Kemp unloaded his harshest attack yet on Lt. Gov. Casey Cagle with a letter to the National Rifle Association warning it is "getting played" in the race for Georgia governor.

In a dispatch sent late Wednesday to NRA chief executive Chris Cox, Kemp accused Cagle of defying his broad promise to “kill” any legislation that would benefit Delta Air Lines because of a mass transit measure that could exempt jet fuel from a local transportation tax.

“As those of us involved in Georgia politics like to say: You’ve been Casey Cagled,” wrote Kemp, Georgia’s secretary of state. “He tells you one thing while cutting secret deals to help Delta down the line.”

Cagle's office said the legislation extends exemptions for sales tax on jet fuels if Cobb and Gwinnett counties vote to raise sales tax to join MARTA and would not apply to Clayton County – home of Hartsfield-Jackson and Delta's hub - because it has already approved joining the transit system.

His campaign said the letter smacks of desperation and that there’s no hidden benefit to Delta.

“The only way this helps Delta is if it lands a 747 in Gwinnett or Cobb County regional airports,” said his campaign manager, Scott Binkley.

“Brian Kemp should go to one of them to save on his next purchase of jet fuel he was sniffing before sending out that statement. He is obviously as clueless about legislation as he is about protecting voters’ personal information.”

Cagle earned national attention in February when he announced his opposition to a jet-fuel tax break that would have saved Delta about $40 million a year shortly after the Atlanta-based airline severed business ties with the NRA.

The airline said ended discounted rates for NRA members because it wanted to remain “neutral” in a growing gun control debate, but Georgia conservatives have long accused the airline of trying to influence state policy in other areas.

The tax break was at the top of Delta's legislative wish-list, and it initially had the support of Gov. Nathan Deal and a host of powerful lawmakers. But Cagle's stance effectively blocked it from becoming law, and the governor was forced to sign an income tax-cut measure into law without the jet fuel incentives.

A poll by a Cagle-aligned group suggested his standings in the May 22 contest had slightly improved after the tiff. The lieutenant governor is leading in public and private polls, and there's a tight race for the second spot in a likely July runoff.

Kemp and the other three GOP candidates for governor – former state Sen. Hunter Hill, business executive Clay Tippins and state Sen. Michael Williams – also backed stripping the Delta break. Williams had actively fought to remove the incentives weeks before the NRA tiff exploded.

The two Democratic candidates for governor, former House Minority Leader Stacey Abrams and ex-state Rep. Stacey Evans, accused Republicans of playing politics with Georgia's largest private employer.

And other critics, including corporate boosters, worried aloud that the maneuvering had cost Georgia a shot at Amazon's second headquarters or other big-name economic development recruits.

In his plea to Cox, Kemp wrote that Cagle’s team “will throw all sorts of confusing jargon and legislative baloney at you trying to deny”  that he violated his oath to punish Delta.

“It’s complicated legislation that they will undoubtedly try to make more complicated when they explain it to you,” he wrote. “But the facts are the facts. Delta benefits in the near future from this legislation that Cagle supported.”

The NRA has yet to formally endorse a candidate in the race for governor, but the group posted its thanks to Cagle on social media. Kemp’s push – which also included a list of his supporters who have high NRA ratings – could be an effort to convince the group to stay neutral in the final weeks of the GOP race.

While the NRA's endorsement remains coveted among Republicans, the Democratic contenders are feuding over just how much they loathe the gun group. Abrams and Evans have repeatedly clashed over votes on issues the NRA has backed and each vowed to be the gun lobby's enemy.

Read Kemp’s entire letter below.

Other recent AJC coverage on the Delta flap:

Georgia legislators punish Delta, but Amazon may be watching

GOP spin to Amazon: NRA dustup shows Georgia's 'diversity’

Amid NRA-Delta tax break battle, others woo Delta headquarters

Georgia Democratic candidates used to court pro-gun votes

Chris,

As you know, I am a Republican candidate for Governor of Georgia. My opponent Casey Cagle made quite a spectacle trashing Delta Airlines this legislative session trying to show he is a strong supporter of the NRA. I'm quite sure he has been pushing for, if not demanding, your endorsement now that the session is done. 

He has probably brought up to you and others this tweet:

I will kill any tax legislation that benefits @Delta unless the company changes its position and fully reinstates its relationship with @NRA. Corporations cannot attack conservatives and expect us not to fight back.

That sounds real good. But there's one big problem with it. 

The NRA is getting played. 

Please have your team review HB930 from this past legislative session. It passed on the last day (aka Sine Die). It is a legislative package to expand mass transit in Georgia, especially in the metro Atlanta area in which Hartsfield-Jackson Airport is located. 

This legislation does not include the comprehensive jet fuel tax break that Delta Airlines sought earlier in the year, but it does grant to airlines at Hartsfield (notably Delta) an exemption from a local transportation sales tax known as TSPLOST that Clayton County may levy in the near future. 

Clayton County is where Hartsfield Jackson airport is primarily located. The exemption applies to any airport that has more than 750,000 takeoffs and landings per year. In Georgia, the only airport that qualifies is Hartsfield Jackson.

As those of us involved in Georgia politics like to say…..you've been "Casey Cagled". 

He tells you one thing while cutting secret deals to help Delta down the line. 

I know that Cagle's team will throw all sorts of confusing jargon and legislative baloney at you trying to deny this. It's complicated legislation that they will undoubtedly try to make more complicated when they explain it to you. 

But the facts are the facts. Delta benefits in the near future from this legislation that Cagle supported. 

Chris, I have been a member of the NRA for many years. I hunt, fish, and carry. I have served in the State Senate and have a rock solid voting record on 2nd Amendment issues. Most importantly, I will tell you where I stand and I don't waver. I do what I say in everything that I do. 

In stark contrast, the record of what you get with Casey Cagle is crystal clear. 

If you are interested in having someone in this important office who believes as you do and will not play these kind of games, I welcome your support and ask for your endorsement. 

Thanks for your time and consideration.

Brian Kemp