The true art is:
1) First lure these Republican trolls out from under their bridge.
Usually a positive word about one of their candidates will get them out into the sunshine, out of curiosity, if nothing else. Try "Schwarzenegger is good for the Republican Party"
2) Then provoke them into climbing up the creek embankment to better do battle
Stick to politics, keep it impersonal and don't mention facts whatever you do. I'd suggest " But if Schwarzenegger keeps going left, the CaGOP will be in shambles bu 2010."
3) Once the troll is out of the creek bottom, on the shoulder of the highway, interject something personal that will drive them, in a rage, onto the public highway.
I personally prefer " Your associate Duf is an incompetent fool. Prominent party officials are demanding an investigation right now for corruption"
The combination of their poor eyesight and blind rage will make them a perfect target for a drive-by Democrat.
After the collision flee. The odor is overpowering.
A FoulOdor, at that.
Happy Thanksgiving to ya!