Aside from campaign stops, one of the best ways to tell if a candidate thinks a state is really still in play is TV advertising. If they keep buying ads, it's a sign the campaign thinks it's still at least a worthwhile investment -- especially now, with the conventions over and the 48-day sprint to the elections underway.

By that measure, the Obama and McCain campaigns see three Southern states -- Florida, Virginia and perhaps most surprising, North Carolina -- as still-hot battlegrounds. Political Wire gives this report, fresh out from the Wisconsin Advertising Project:

The Obama campaign aired ads in seventeen states from September 6-13, while the McCain campaign aired ads in fifteen of those same states.

McCain and Obama are roughly even in spending in Colorado, Florida, Michigan, New Hampshire, New Mexico, Nevada, North Carolina, Ohio, and Wisconsin. Obama is out-advertising McCain by nearly 3:2 in Missouri and by nearly 3:1 in Virginia. ...

Said project director Ken Goldstein: "Where the campaigns advertise tells us a great deal about the candidates' electoral strategies. Post-convention ad buys give us the first insights into the campaigns' assessments of where they think they are competitive as the fall campaign heats up."

This qualifies our earlier assessment that Obama may be de-emphasizing North Carolina -- although it does confirm that Obama sees Virginia is their top Southern target.