Herschel Walker wants Rep. Jack Kingston (R-Ga.) "carrying the ball" for Georgia in the U.S. Senate.

That's what the football standout says in a new campaign ad paid for by the U.S. Chamber of Commerce, which backs Kingston in the Republican primary. Walker is a Georgia native who won the Heisman Trophy (college football's highest honor) as a running back at the University of Georgia and went on to play in the NFL. Many Peach State viewers will recognize him when they see the ad.

Putting recognizable faces front and center has been a central part of the chamber's ad strategy this election cycle. It's a potentially effective way to do something that's typically difficult for outside groups: Run a positive ad for a candidate.

Take the ad the chamber cut for now-Rep. David Jolly (R-Fla.) in this year's special election. It featured Jeb Bush, the well-liked former Florida governor, who is practically universally known among Sunshine State voters.

Or the commercials for Rep. Cory Gardner (R-Colo.) the group released featuring Sen. Marco Rubio (R-Fla.). Rubio cut versions in English and Spanish, serving as a key ambassador for Gardner to the state's many Hispanic residents.

Other groups have also deployed similar tactics. The GOP-aligned American Crossroads turned to former secretary of state Condoleeza Rice to make a pitch for Senate candidate Dan Sullivan (R) this year.

It tends to be harder for outside groups to run positive spots because such ads often work best when the candidate is the one speaking. But since these groups are barred from coordinating with campaigns, this becomes tricky.

There are workarounds — campaigns often post clip reels and opposition research online for anyone inclined to use them to make an ad — but running a positive commercial is always going to be more difficult for third-party groups than for campaigns.

That's where surrogates who come from both in and outside of politics come in. They put a face and a name behind a given candidate. That's why it's safe to say Walker won't be the last well-known supporter to appear in an ad during the midterm campaign.