The National Republican Senatorial Committee has reserved $5.5 million worth of airtime in Virginia this fall, another clear sign that the GOP campaign arm views the state as a key battleground.

George Allen is getting some advertising help from national Republicans. (Stephanie Klein-Davis — AP Photo/The Roanoke Times)

Simply reserving the airtime now does not necessarily mean that the NRSC will run $5.5 million worth of ads in the state. The committee could decide to shift some of that money elsewhere, or it could decide to pour even more into the Allen-Kaine contest. Buying the airtime early allows the NRSC to get its desired times at lower rates.

The NRSC’s reservation is the latest indicator that Virginia’s race w ill be one of the nation’s costliest races. The Democratic Senatorial Campaign Committee is also likely to put money into the state, and so-called “super PACs” have already emerged to benefit each candidate.