right of publicity -- the right to prevent others from using your name, image or personna for commercial purposes -- extends to all people (and yes, politicians are people). However, we don't think you will get hassled for two reasons. First, politicians have historically been hesitant to hassle merchandisers because of the possible political fallout. Second, politicians usually don't want to get entangled in the first-amendment arguments that arise when a merchandiser fights back. (For example, the maker of a Governor Arnold Schwarzenegger bobblehead argued that his product was a three-dimensional political cartoon.)
P.S. Even presidents sometimes wade into the merchandising free-for-all (yes, presidents have a right of publicity as well).