The Associated Press reports that groups backing Republicans have booked $6.8 million in TV time, with the Karl Rove-associated group Crossroads GPS booking $5 million of the total. 

 

The Democratic Senatorial Campaign Committee and the Senate Majority PAC -- both backing Democrats -- have reserved $11.8 million in TV time.

 

The money is just one piece of $80 million set aside in key Senate races across the country.

 

Republicans must pick up six seats to win control of the U.S. Senate. Kay Hagan's North Carolina seat is one of the key seats that could turn the chamber to Republicans or keep it in the hands of Democrats.