The top Republican on the House Armed Services Committee is worried that a hot-button debate over military base names that honor Confederates could kill this year’s defense authorization bill.

Rep. Mac Thornberry of Texas told reporters Tuesday that House and Senate negotiators are making progress writing a final NDAA for fiscal 2021. But he said outstanding political variables “above our pay grade,” led by the Senate runoff elections in Georgia on Jan. 5, have some in Congress favoring delaying the NDAA into 2021 rather than dealing now with difficult questions such as the Confederate base names.

Both the House and Senate NDAAs, which set Pentagon policy, would require that Confederate base names such as Georgia’s own Fort Benning be changed, making the issue a particularly prickly one for the Peach State.

President Donald Trump has vowed to veto any bill containing such a provision. Trump has also criticized numerous other provisions in the House-passed bill. Thornberry said he has no doubt that the conferees can reach agreement on reconciling differences between their bills on the central defense issues.

“The question,” he said, “is will the politics above us allow us to?”

Thornberry called delaying the NDAA into next year a terrible idea.

Before delivering a speech at the conservative Heritage Foundation in Washington, he said that because of the upcoming inauguration and the formation of committees in the new Congress, the process of writing an NDAA would essentially have to start over in 2021.

“If we don’t get the NDAA done before the end of December and signed into law before the end of December, then all of those provisions just die and the new Congress would have to start from scratch,” he said.

Thornberry, who is retiring at the end of this Congress, noted that the NDAA has become law for 59 straight years. The House’s version of the bill is named after him.

“It would be a shame for any of us to have a role in blowing it for number 60,” Thornberry said.