This was obviously cooked up by idiots. There would be no point to putting a transmitter on Bush. Everyone can hear him just fine, and with the Secret Service all around him, I doubt he'd be lost.
Now, if the afore mentioned retards were refering to a RECEIVER, then it's still rediculous. For one, the size of a reciever needed to pick up a signal from that far away would be extremely small, especially if the transmitter were more powerful. The only thing of size in such a thing would be the battery, which would be either hidden in the pocket or also be so small as to be invisable. Also, placing such a device on the back between the shoulder blades is idiotic. It would be hard to stick it there in such a way that it wouldn't come loose with movement, such as shaking hands vigerously and patting each other on the back after the debate. THAT's even for moderately ranged devices. In this environment, something in the ear, or placed in side the mouth, along the jaw, would have been much more likely.
Of course, no one expects tabloids to be believable...