That question, issued in apparent defiance and frustration that she could actually be called to account, is a question which will hang round Hillary's neck forever....Much like her hubby's infamous, "I did not have sex with that woman!"
"At this point what does it matter?" It matters because, after either you knew of repeated calls for additional security help from a near-frantic Ambassador of The United States and ignored them, or you were so out of the loop that the indications are you do not run anything, but delegate even the highest decisions to your minions.
"At this point what does it matter?" It matters because you told both your daughter and the Prime Minister of Egypt, within a day of the Benghazi event that it was terrorists, but continued thru days of public comment to specify that a near-unknown and unseen video was responsible...to the public, to the media, and most significantly to the family and parents of the victims of your lack of judgement in a face-to-face with them.
"At this point what does it matter?" It matters because this entire event was hidden, buried, shoved below the radar so far by you and your willing minions and fellow-Democrats that to this day we still have only a partial picture. Because the President you wish to emulate and follow for 4 more years, still hides and obfuscates those who were there; and their information, which almost certainly is NOT friendly to your lies and deceit.
"At this point what does it matter?" Because, Madam Secretary....it tells the entire tale of your lack of character, truthfulness, and fitness to to be our Commander-In-Chief. What military/Ambassadorial/foreign-service professional would ever feel safe....and, why would the citizenry of this country trust you to do anything but feather your nest, and cover for any and all miscreant actions by yourself and your minions.
"At this point, Madam Secretary, it matters more than ever!"