Wait, the San Bernandino shooting is constantly referred to as terrorism by the media and by politicians... When the perpetrator isn't Muslim though, the situation is different (e.g. Dylan Roof, Anders Brevik, James Holmes) and the same people instead are much more likely to frame the violence as a mental health issue.
I see no meaningful distinction between the San Bernandino shooters and the "lone wackos". Cultural background influences how an angry, mentally ill person will brand and target their particular act of violence. For Dylan Roof it was racism, for Anders Breivik it was Christianity, and for Syed Rizwan Farook and Tashfeen Malik, it was radical Islam. So far even the FBI says they acted alone.
It's undeniable that whether or not a person is Muslim influences how their violent act is framed by the media and politicians. Also worth noting: