The vociferous defenders of any political party always risk being the target of both praise and distain ...so here's what Yahoo Answers weighed in with as the best definition of a political shill as chosen by the voters.
POLITICAL SHILL - A person who debunks detractors of a ...political party. They may not know the horrible truth about the one they serve. Basically, any person who supports defending any political candidate falls into that category.
The ones who do not know the truth about their masters are more appropriately called usefull idiots.
Hope this little bit of humor brightens your day