Yeah, I agree. There is probably complete deniability at the Presidential level. A few underlings will have to go, maybe even Holder,and some serious embarrassment will ensue, but that's it. Don't expect Obama to resign.
But don't be surprised. Everything has been going off-script for those people. We've been disappointed so many times with Democratic scandals that go nowhere, but this thing is breaking worse and worse. When Clinton's trash started catching up with him, he had Reagan-Bush's economy to discourage widespread discontent. But this atmosphere is different. Nobody's happy with this clown, and that encourages stray negativity that snowballs.
Part of what happened to Nixon is that a lot of people, including conservatives, were mad at him—adding to the core of Stalinists who were still sore about his nailing Hiss. It's too long before the election before the Dems will start closing ranks. For Barky, this is the worst possible time for this stuff to be breaking.