It's safe to say that behind the scenes Democrats are in full-blown panic mode.
NBC's Lisa Myers, in a panel discussion on MSNBC, revealed: "There is something called Benghazi going on, and I think the Democrats now are starting to worry about it. It's started. I got calls from a number of Democrats yesterday trying to undermine Greg Hicks’s testimony, saying he wasn’t demoted. So I think they feel that some damage was done by those three witnesses on Wednesday."
Myers was interviewed before the blockbuster revelation by ABC News that the State Department and/or the White House lied about the Benghazi assassinations.
I surmise the reason that the White House was behind the release of the email revision history: Obama wants no taint to his legacy (such as it is) and if Hillary Clinton needs to suck it up, so be it.