Following up on David's post below, why is McCain outspending Obama two-to-one in Missouri?

We had reader reports suggesting this last week. And in response to those reports readers from a number of other swing states reported seeing the same thing -- a flood of McCain ads and only a much smaller number of Obama ads.

When we checked in with Obama campaign, the impression we were given was that this was more a matter of viewer perception than reality. But the Post-Dispatch's reporting makes it clear that in Missouri at least it is very much the reality.

I've got my hand on only a small patch of a national campaign elephant. But voter preferences are much more malleable in these early summer months than in the Fall. So I am curious to know why what we're told is the heavily outfunded campaign is dominating the airwaves in at least some key areas.