Influence Alley

Sure, South Carolina's primary voters will play a big role in winnowing the GOP presidential field next Saturday, but a look at Florida's television screens might be an even better predictor of who stays and who goes. 

The six GOP candidates and the super PACs supporting them have spent almost $32 million on television ahead of Florida's Jan. 31 primary, according to a recent review by an ad buyer obtained by National Journal. And with early voting already under way in the Sunshine State, at least some percentage of Florida Republicans will have already cast their ballot by the time the results in South Carolina are known. 

With millions already invested, a few candidates may not let a poor showing in the Palmetto State stop them from heading south. Consider how much the candidates and the super PACs supporting them have already spent on ads:

Mitt Romney and Restore Our Future: $11.5 million

Rick Perry and Make Us Great Again: $9.3 million

Ron Paul and Santa Rita PAC: $5 million

Newt Gingrich and Winning Our Future: $3 million

Rick Santorum and Red, White and Blue Fund: $1.1 million

Jon Huntsman and Our Destiny: $2.1 million 

With sunk costs of $9 million and $5 million, respectively, it would not be crazy to think that Perry and Paul stick it out to Florida almost regardless of how they do in Carolina. Gingrich, on the other hand, either needs to beat expectations or land another big super PAC check to continue.

Short of an enormous super PAC investment, none of the candidates is likely to catch the spending of Romney and Restore Our Future. In fact, Romney is the only candidate to have reserved airtime in Florida, about $220,000 worth, after the South Carolina primary.