I thought it was just a rumour too until I actually saw the picture.
http://www.nytimes.com/2004/10/09/politics/campaign/09bulge.html
The Mystery of the Bulge in the Jacket
By ELISABETH BUMILLER
Published: October 9, 2004
ASHINGTON, Oct. 8 - What was that bulge in the back of President Bush's suit jacket at the presidential debate in Miami last week?
According to rumors racing across the Internet this week, the rectangular bulge visible between Mr. Bush's shoulder blades was a radio receiver, getting answers from an offstage counselor into a hidden presidential earpiece. The prime suspect was Karl Rove, Mr. Bush's powerful political adviser.
When the online magazine Salon published an article about the rumors on Friday, the speculation reached such a pitch that White House and campaign officials were inundated with calls.
First they said that pictures showing the bulge might have been doctored. But then, when the bulge turned out to be clearly visible in the television footage of the evening, they offered a different explanation.
"There was nothing under his suit jacket," said Nicolle Devenish, a campaign spokeswoman.
"It was most likely a rumpling of that portion of his suit jacket, or a wrinkle in the fabric."
Ms. Devenish could not say why the "rumpling" was rectangular.
Nor was the bulge from a bulletproof vest, according to campaign and White House officials; they said Mr. Bush was not wearing one
