Delta says only 13 people used its NRA discount.

The airline's decision to end the discount cost it a tax break in Georgia that would have been worth tens of millions of dollars.

Delta (DAL) was offering discounted travel to NRA members heading to their annual convention in Dallas in May. But it pulled the offer on Saturday, under public pressure after 17 people were shot to death at a high school in Florida.

The decision angered Georgia Republicans, who stripped an exemption for jet fuel out of a tax bill that was signed into law on Friday.

Related: Delta CEO: 'We are supporters of the 2nd Amendment'

USA Today first reported on Friday that only 13 people used the discount.

The airline, based in Atlanta, said on Friday that it meant to stay "neutral" in the debate over gun control.

"We are supporters of the 2nd Amendment, just as we embrace the entire Constitution of the United States," Delta's CEO Ed Bastian told staff in a memo.

"Our people and our customers have a wide range of views on how to increase safety in our schools and public places, and we are not taking sides," Bastian added.

Related: Why Delta and Atlanta need each other

In the memo, Bastian said the airline has started a review and will end group discounts for "politically divisive" organizations. Delta did not offer details on that process, including what qualifies as politically divisive.

More than a dozen companies distanced themselves from the NRA after the school shooting in Florida. United Airlines (UAL) also stopped offering discount flights to the NRA conference.