An excellent article discusses how the media and the DNC are trying to promote this idea that "right-wingers" are making threats and attacking the DNC. I am very wary of any of these reports, as many turn out to be false.
For example, a popular story about a coffin being placed on a Democratic lawmaker's front lawn ended up being totally false. Source
It has also been pointed out that the calls released from Stupak's office were most likely those from Democrats who supported abortion and were angry that Stupak was holding up the healthcare legislation vote over the issue. These calls have been misrepresented as "right winger attacks" on some media stations.