1. Impersonates another and does an act in such assumed character with intent to obtain a benefit or to injure or defraud another;
No, I don't think it's at all ridiculous. The call was quite obviously intended to injure the reputation of the Wisconsin Governor. Period.
We've endured the tedious bleating of the MSM and the Democrats about the "new tone" of "civility" in the political sphere, and we all know it's unadulterated BS. given the current environment, I do not think it is unreasonable to view this "stunt" through the lens of the kind of political hatred which obviously was a factor in the Giffords shooting. (Sarcasm intended, but payback is a bitch.)
Therefore, it's a fairly minor misdemeanor in New York, but it's still against the law.
There's no "injury" here that could ever serve as the basis for a criminal prosecution.