This could indeed be a purge. If a clampdown is imminent, the first thing its leaders would wish to do is ensure that the nation’s nuclear arsenal is under the control of generals and admirals who are personally loyal to the leaders.
In the end, however, the success of a clampdown depends upon the willingness of the U.S. soldier or Marine to fire upon U.S. citizens. Our armed forces have been employed against American citizens on several occasions; there is no reason to believe most soldiers today would balk at shooting you or me if so ordered.
A leftist will ne reluctant to use even a purged military to deal with his enemies (leftists have no "opposition" only enemies). They would rather use a militia built by them from the ground up. Husein is the most serious about this of all the Social Democrats we have had. Remember his call for a very well financed civilian defense force? $-8 bil for ACORN is a start on this. It will buy a lot of brown or purple shirts and the "defunding" that just occurred was temporary and will be reinstated either to ACORN or to whatever other name that organization will use.