I have a theory that this employment termination happened when it did so the media and other liberals would focus on James Comey instead of another action that will have a much larger impact on draining the swamp; namely, President Trump announcing the formation of a special commission to investigate voter fraud.
Done correctly, this will lead to even more deportations of illegal aliens who voted in recent American elections, and actual requirements for voter ID.
And with Mike Pence involved, I expect this will be done correctly. All of this will happen while the Dems and MSM are obsessing about James Comey.