Up until WWII, the people possessed superior force. Roosevelt dealt a deathblow to that power in 1944, at Yalta. By empowering the Soviet Union as an enemy, the national government instituted a massive standing army. Since that time, the ACLU has enlarged police power via the courts. Hence your question.
I don’t fear the “standing army”....I fear the unionized para-militarized law enforcement agencies and their assorted tanks, billions of rounds of ammo, and NSA spy suite.
The Army/Marines are the least of worries and might actually prove to be a check against the numerous 3 letter agencies.