The allegations of "left-wing violence" have been greatly exaggerated, and the Faux-News-inspired hysteria has led Republican politicians to live in fear. State Senator Dan Kapanke canceled public appearances based in part on an erroneous belief that someone had deliberately smashed the windshield of his car. It turns out that the damage was done by a stray rock thrown up by another vehicle -- a normal road mishap that many of us have experienced.
The email death threats were absolutely wrong, and the woman who made them is rightly facing felony charges. It turns out, though, that her motive may have been to frame another woman (whose identity she spoofed to make the emails) with whom she had a personal conflict.
Like the allegations of wide-spread voter fraud and the existence of palm trees in Madison, the left-wing-violence meme has taken root in the mythology of the tribe who take Sarah Palin seriously. It seems to me, though, that encouraging your leaders to live in fear is not a winning strategy.