"For weeks, conservatives fought the good fight to cut spending and defund ObamaCare. Lamar Alexander however, was behind closed doors trading favors," Carr says.
"Amid the chaos, Lamar snuck in $3 billion for a dam ... like this one. Three billion for a dam? No darn way," he adds.
The ad will run statewide on Fox News and online for the next week.
It's a reference to funding for the Olmsted Locks and Dam project currently under construction on the Ohio River that was included in the deal that ended the shutdown.
The provision increased funding for the project from $1.7 billion to $2.9 billion, and it outraged conservatives, who deemed it the "Kentucky Kickback" and hammered Senate Minority Leader Mitch McConnell (R-Ky.) for its inclusion in the shutdown deal.
Conservatives believe it's an example of the out-of-control spending that has caused the debt and deficit to balloon in recent years.
But Alexander has previously said the funding was needed because the project would stop next month without it, and that $160 million "will be wasted because of canceled contracts if this language is not included."
Alexander's campaign manager, Alice Rolli, further explained the reasoning behind the funding in an email, arguing it's necessary to ultimately save taxpayers money.
“If Pinocchio had written this campaign ad, his nose would be a foot long. According to the Army Corp of Engineers, instead of costing money, this provision actually saved taxpayers $160 million in canceled contracts and restart costs. It had already been approved once by the House and Senate this year and only allowed spending already appropriated," she said.
She noted that one-fifth of all traffic on the American Inland Waterway system goes through the lock, and every time a boat passes through, serious repairs need to be made.
Still, the funding offers conservatives a symbol that they say is emblematic of the government waste they're running against, as evidenced by Carr seizing on it in his first ad.
Carr said in a statement accompanying the ad that he would've opposed the shutdown deal.
“Sen. Alexander sold out conservatives while pushing a $3 billion pet project in a backroom deal. I would have voted against the Reid-Alexander compromise and never would have fought for a pet project. That’s a real difference between Sen. Alexander and I that voters should know about,” he said.
Watch the ad:
— This piece was updated at 3:08 p.m. to reflect comment from Alexander's campaign.