If you need a little help in understanding what the big deal is about Benghazi, perhaps this little thought experiment will help. Suppose you are involved in an automobile accident, and when the insurance adjuster calls to ask a few questions about the incident, you describe the event as a car "crash." When you are later quizzed again about the same mishap, you call it a car "collision." This use of a different label for the accident leads the insurance company to cancel your policy and accuse you of fraud.
The Obama administration initially said the Benghazi incident exploded from a "spontaneous protest" into deadly violence. They later called it "terrorism." The change in verbiage has apparently grown to become "the worst scandal in US history."