No, I don't think he's got one. They are extremely rare, and expensive. My interest in the breed dates back to childhood, long before John Kerry rose to fame. A relative had some as part of the kennel she ran.
The breed does require more grooming care than any other save for the poodle. Kerrys also love to spar with/attack other dogs, and will kill small animals in the neighborhood. IOW there are some similarities to candidate Kerry.
I don't know if I'd call Kerry Blues "rare" (see: Wirehaired Pointing Griffon), and for expensive call the Euro GSD nuts. Anyway, I'm sure Kerry could afford 1 if he wanted a dog who matched his name for some kind of cutesy publicity ploy. ;-)