Astroturf, in the political lexicon as I understand it, is fake grass roots. You know, where some group has an interest in some outcome but disguises its efforts to get that outcome by dressing up as being opposed to that effort. Anyway, that's how I understand it. Here's another definition.
I just read about how John McCain got an earful of anti-immigration reform anger. The Tea Party types and their ilk just hate the idea of giving the Browns a path to citizenship. Some hate "rewarding" people who broke the law. Some think that the Browns will vote Democratic once they gain citizenship, and thus should not be allowed that citizenship. And some are just straight up racist. But whatever the motivation, they don't want any path to citizenship.
Problem is, Republicans have to make some effort toward this, seeings as how the Browns are the fastest growing segment of the population, and they tend to vote Team D. If the Rs keep rejecting and/or pissing off the Browns, they're going to end up on the losing side of demographics. And they know this.
So to defuse the issue, the Rs are trying to talk up reform, and seem somewhat amenable to reform, even to some possible path to citizenship. Which puts them at adds with their base. How to woo the Browns yet not alienate their base, that is the question.
So I say, D activists should go to R town hall meetings, pose as Tea Partiers, and stir up the crowd against reform. Think back to the town hall meetings in which Dems got savaged by idiots thinking that Obamacare included provisions to euthanize seniors. That alone almost killed it. Let's return the favor and harden base sentiment by rabble rousing (respectfully, of course) in the R town hall meetings.
That will work on two levels. One, it will make it harder for the R politician to vote for meaningful reform, and two, reports of the meetings will resonate with the Browns and reinforce their antipathy for the R party. It's a win-win for Democrats.