If there is one thing the purging of US Attorneys can show us about the administration, it's how much mojo the administration has lost, and how patently unaware of this fact they are. Let's take a look back at another US Attorney that was fired for prosecuting those who the administration sought to protect.
In 2002, one day after issuing subpoenas in an investigation of Jack Abramoff, the US Attorney for Guam, Frederick Black, was dismissed from the position by the administration. Do you remember hearing anything about it at the time? Probably not. It was as far off the radar screen as you can get.
In fact, I'd wager that the administration figured that since it drew no attention then, getting rid of some more US Attorneys who were or were not prosecuting the right people now would be no problem.
The administration was wrong though. This administration is now as lame duck as they come, and everything they do will be scrutinized with a fine tooth comb. The mojo is gone, and it isn't coming back.