Note that the U.S. Army "may be called upon to help with civil unrest and crowd contro...." (My understanding is that this violates a law from 1807 prohibiting the use of the military for police functions within U.S. borders.) See the quiet announcement of this buried in the Army Times:
Brigade homeland tours start Oct. 1 - Army News, opinions, editorials, news from Iraq, photos, reports - Army Times
Brigade homeland tours start Oct. 1 - Army News, opinions, editorials, news from Iraq, photos, reports - Army Times