GatorDoug has an ex plainer of "astroturfing" via Jimmie at The Sundries Shack:
A little history is in order. The term AstroTurfing came about to describe efforts to make a protest look like it came from the grassroots (i.e. unorganized groups of ordinary folks who’ve come together in more or less an impromptu manner). It became commonplace in the last election when professional AstroTurfer David Axelrod became a top adviser to the Obama campaign. Jim Treacher was the first to really dig into Axelrod’s operation and you can get a good chunk of background on what he was doing in this post.
Basically, astroturfing is taking a real issue and ginning it up with fake plants, for example paying people to turn out in support of ObamaCare.
Currently, the Left, led by the father of AstroTurfing, David Axelrod, is accusing the Right of planting faux opposition at the health care town halls. Having been to both a Tea Party and a town hall I find the accusation laughable and more than a bit desperate. For instance, did my local 912 Project group put out info about my local union sponsored town hall? Absolutely. Did they bus in an angry mob in matching tee shirts and professionally made signs? Um, no, that was the other side.
I get that the Left needs to downplay the passion of the grassroots movement against ObamaCare. As the polls show that ObamaCare is tanking, they know that admitting that ordinary citizens are coming out in droves to oppose the government takeover of health care would be the final nail in the coffin. What they don't seem to get is that they are energizing the anti-ObamaCare folks with each falsehood they put out.
Let them keep talking about astroturfing, thugs, mobs, Nazis, etc. It is the gift that just keeps giving.