Another interesting data point from Nielson, which has been tracking campaign commercials.

This is their chart of daily ads run in Colorado:

As we can see, McCain has been pulling back in the Centennial State. On Tuesday the 21st, his campaign ran 135 ads in the markets that Nielson monitors. This Tuesday, he ran just 55. That's a 60% decrease.

Meanwhile, here is what Pennsylvania looks like.

Last Tuesday, McCain ran 249 ads in monitored markets in the Keystone State. This Tuesday, he ran 337 ads. That's a 35% increase. Meanwhile, McCain has upped his ad buys in Ohio and Virginia.

What the heck is McCain up to? I have an idea. This is the picture of the primary results for Obama versus Clinton in Appalachia (courtesy of Sean Oxendine).

Meanwhile, the candidates are heading back to Iowa. Sarah Palin had two events there on Saturday, and Barack Obama will be there tomorrow. What's up with that?