Here Are the Origins of Benghazi Fever
In a nutshell, it's shame at their initial, vile response to the attacks.
Read what Martin Longman says today about Benghazi. If you want to understand the origins of Benghazi fever in the fever swamps of the right, I think he has it right. It was basically born out of shame at the initial conservative reaction to the attacks combined with rage that they finally got called on their vile behavior, which ended up helping Obama win reelection.