I've noticed that (here in Bozeman, MT at least) MANY Tea Party members are democrats (including my roommate). I think that this anti-TP campaign is simply aimed at the hateful portion of the democrats, the rather disgusting folks who are disgusting to ordinary people on both sides, mind you.
Guaranteed that this anti-TP place is NOT a "nationwide network of Democrats, Republicans, and Independents" - such a group wouldn't go on to call Tea Party-ers a "loose affiliation of racists, homophobes, and morons", nor would they call it a "fake grass-roots movement" if they wished to retain any credibility.
That in mind, I suspect two possibilities - one, that this was started by a very disgusting democrat as an honest attempt to discredit the TP, or, two, the possibility I find much more likely... that this group was started by a pro-TP individual to get pity and gain support that way. It's... odd to think that way, but hey, politics are like that.