The Republican Governors Association is hitting the airwaves in the Georgia governor's race with an ad hitting state Sen. Jason Carter (D) on the federal health-care law, the latest sign that Carter is an increasingly real threat to unseat Gov. Nathan Deal (R).

"We know Obamacare is making health care coverage more expensive. Costing us jobs. And forcing people to pay for things they don’t want or need. So why would Jason Carter say expanding Obamacare 'should be on the table?' We don’t want more Obamacare," says the narrator of the 30-second TV ad.

The ad comes as polls show Carter, the grandson of former president Jimmy Carter, in a tight race against Deal.

"This ad is nothing but an acknowledgment that Gov. Deal is flailing and his campaign is in serious trouble," Carter spokesman Bryan Thomas told the Atlanta Journal-Constitution.