From an outside perspective, it's very, very difficult to unwind this situation. One possible (but v.unpalatable) solution is to offer absolution to members of the admin who switch sides. Such as the middle-ranking opportunists who are only in it for themselves. Very bitter pill to swallow though.
We can always betray them later
There is no easy answer to this situation. There is probably no solution that doesn't involve unpleasant compromises and grubby deals which will be very hard to swallow. But this is all for the future - a lot of things need to happen first.
Something far less serious happened with the Bush-Obama transition. There was no real prospect of the Bush people trying to stay in power to forestall prosecution, though, & Obama just unilaterally said we're not going after them. A different time, but one that normalized impunity for, like, treason