It ties in perfectly to liberals' attempts to frame the Tea Party movement for racism.
Every time someone comes to a Tea Party demonstration with a blatantly racist sign, the person in question inevitably turns out to be a liberal "Infiltrator" just trying to discredit the Tea Party.
Heck, a few years ago there was a DU thread where one DUmmy was asking for advice on how to dress when infiltrating a Tea Party (The other DUmmies suggested wearing a shirt with a teddy bear holding an American flag, and bringing a sign with a picture of Obama as a monkey, failing to realize that anyone coming to a Tea Party demonstration with such a sign wuld be immediately recognized as an "Infiltrator" and thrown out).