A few facts are clear: The assault was not a spontaneous demonstration in response to the notorious video mocking the Prophet Mohammad—a demonstration that simply spiraled out of control. Even the nasty, but less violent, demonstrations in Egypt, Iraq, Yemen, and other Muslim countries do not fully fit that description, and the Libya attack was fundamentally different from all of those other incidents. The assault in Benghazi had all the earmarks of a well-planned, well-coordinated, professional military operation.
The association of this video with the violence began with various government officials, most of whom bear some responsibility for the conditions on the ground in the Middle East.
The left/right divide is still obviously evident in this country, and it is especially obvious in the right's abject failure to see through this flimsy lie. Instead of noticing the terrible strategic position we are in, the right appears to be assuming this is merely evidence of Obama's inability to be bellicose enough. Military actions has been expanded and continued throughout his term.
But so many seem wed to this idea of a religious war, with Islam being an implacable enemy, despite Saddam, Gaddafi, and various other little gadflies being more properly termed Fascist (Baathist), Communist, etc... The violent ideologies breed violence. Conservatism tends to be somewhat non-ideological, but officials have understood how to handle them since Bismark- a psychological sleight of hand, linking the nation to family. Thus military service, and various government projects ancillary to the military become sacred. A huge chunk of the modern state gets a pass. The conservative, sadly, ends up losing because he never sees the mess that has been back-filled into what he assumes are his traditions.