The Civilian branches did not do their duty. This is no excuse for the military not to do theirs.
Under our constitution, the military has no authority to contravene the will of the civilian goverment. Nor does it have any authority to determine whether civilian goverment has done its duty. That is the job of the voters, and the voters alone. The military's duty is to carry out the will of the civilian goverment.
Military subserviance to civilian goverment is a key principal of republican goverment that prevents tyranny. The founding fathers understood this. I'm shocked that so many so-called "conservatives" on this site don't.