"Obama's man in Arizona? Or Jeff FlakeJeffrey (Jeff) Lane FlakeFlake to try to force vote on DACA stopgap plan Congress punts fight over Dreamers to March Outgoing GOP rep: Republican Party 'heading into trouble' in election MORE, Arizona's man in Washington?" a voiceover asks.

The message that Carmona will be a party pawn in favor of all of Obama's policies is one Flake's campaign has been pushing from the outset of the general election cycle, as GOP presidential nominee Mitt Romney holds a solid lead in the red-leaning state. But Carmona has worked to combat that perception, touting his experience as Surgeon General in George W. Bush's White House as evidence that he has bipartisan experience.

According to an ad-buying source in Arizona, Flake's new ad will run at 510 points in the Phoenix area and 360 in the Tucson area — half as much as the recent buy launched by Carmona for his ad, "Both," that frames him as a bipartisan reformer committed to fixing the healthcare system. That spot is running at over 1,000 points in Phoenix and 800 in Tucson, according to the source, and the Carmona campaign is running ads on Spanish television and radio — something the Flake campaign hasn't yet begun to do.

That may be in part due to a cash deficit Flake faced coming out of a bruising primary fight against self-funded businessman Wil Cardon. Though Flake has raised nearly twice as much as Cardon so far, he's spent more than three times as much as the Democratic nominee, and at the close of the last reporting period posted slightly less cash on hand than Carmona.

Flake campaign spokesman Andrew Wilder implicitly confirmed the size of the buy but insisted that Carmona was spending more not because of any deficit in funds on the part of the Flake campaign, but rather because he had a tougher task ahead of him to win the election.

"Richard Carmona needs to spend more to try to overcome the clear fact that he’s President Obama’s handpicked recruit in Arizona and he’ll be a rubber stamp for his liberal policies in Washington," he said in an email.

In response, Carmona spokesperson Andy BarrGarland (Andy) Hale BarrHouse Republicans add 5 members to incumbent protection program House GOP super PAC expands field offices to 27 districts Seven primary races to watch in 2018 MORE cited Carmona's past as evidence that he's "a lifelong independent."

"Dr. Carmona served as Surgeon General of the United States under George W. Bush. Jon Kyl tried to get him to run for Congress. He's a lifelong independent, and nobody's rubber stamp," he said in an email.

The Hill rates this race as "leans Republican," and most recent polls give Flake a lead over Carmona, but Democrats have high hopes for a candidate hand-picked by Obama.

Watch the ad: