McCain has represented Arizona in Congress for 26 years, but recent polls have shown Obama trailing by just the low single digits in the state.
Pressed on why the campaign was advertising in the three states when other battleground states remain tight, Plouffe said the polls were close enough to justify the effort.
"We're just going to give it a go in the last 4 days and see how close we can get it," he said, adding that the campaign's push in the three states would not detract from its efforts in more traditional battlegrounds.
We wrote about the two spots now set to air in the three states, "Rearview Mirror" and "Something," yesterday. Check them out here.
"Something," which Plouffe referred to as a "positive closer," will be airing in Arizona. He said "Rearview Mirror," which links McCain to President Bush, will air in the other two states because "we've seen movement" there. He cited "highly encouraging" early voting numbers in Georgia and noted the campaign has organizations in all three states.
The Obama campaign would not release the size of the advertising buy.