I have also seen this first hand. There is ONE Obama supporter in our office, and for the past week I have overheard him approaching various people trying to convince them to drink the koolaid. The way he told people to do it in that email is only going to piss people off at his supporters, and ultimately him as a result.
This technique works so well for the Hare Krishnas at the airport. People love it when a zealot gets in their face.