According to Nico Pitney at the Huffington Post, Barry Blitt the creator of the satiric cartoon aimed to convey the extreme views out there of the Obamas:
I think the idea that the Obamas are branded as unpatriotic [let alone as terrorists] in certain sectors is preposterous. It seemed to me that depicting the concept would show it as the fear-mongering ridiculousness that it is.
The problem is interpretation. The Obama campaign issued a release condemning the cover as tasteless and offensive. The McCain camp followed with their own condemnation.
It created such a stir that it even got time on the News Hour with Jim Lehrer.
So, is it a message highlighting the absurd rumor-mongering of the right or is it a tasteless and offensive portrayal of the Obamas?
Perhaps, a title would have helped?