During the final week of the Arizona Senate race, supporters of Rep. Jeff Flake (R) and former Surgeon General Richard Carmona (D) are expected to spend almost $7.5 million, according to a Republican source who tracks media buys.

Both sides are investing heavily, although Republicans are slated to outspend Democrats by about a 2-to-1 margin. But the Democrats are packing a punch with this new spot:

https://www.youtube.com/watch?v=Bk3WboVunoA

Republican sources interpret the heavier GOP spending in the final week as a lack of Democratic confidence Carmona’s ability to defeat Flake. But Democratic sources say the Republican spending advantage is a sign of concern on the GOP side.

The amount being spent is somewhat staggering for a state that is not competitive at the presidential level. But it should probably be expected given the advent of super PACs.

Overall spending numbers for the cycle were not immediately available, and media buy tracking is not an exact science. But here is how the teams are spending in the last week, according to that same GOP source:

Pro-Flake:

• Flake campaign: $740K
• American Commitment PAC: $750K
• Club for Growth: $450K
• Ending Spending PAC: $440K
• Now or Never PAC: $820K
• National Republican Senatorial Committee: $1.6 million

Pro-Carmona:

• Carmona campaign : $650K
• American Federation of State, County and Municipal Employees: $540K
• Democratic Senatorial Campaign Committee: $690K
• League of Conservation Voters: $280K
• LCV/Senate Majority PAC: $430K

As for the content of that DSCC ad, which features a cancer patient attacking Flake, it’s a tactic Democrats have used before. Sen. Jon Tester (D) took a similar tack in July against Rep. Denny Rehberg (R) in their Tossup Montana Senate race:

https://www.youtube.com/watch?v=uaB_BSaMzQ4&feature=player_embedded

One unaligned political operative (and a cancer survivor) compared the Arizona ad to this scene, from the Chris Rock movie “Head of State”:

Jessica Taylor contributed to this report.