The % of citizens who feel the constitution is likely due for some change. While not near the 66% in 50 states needed to change it, is likely enough to seriously effect the resources forcing other to follow it.

Even congress and the senate are far from 100% in agreement. Or ever likely to be on such things. The further from the head of the snake you go. The more likely the US military is to question orders to attack domestic targets.

A d lets face it. Any attempt by the military to force orders in a situation like that, where the enemy is considered to be a part of your own team by a significant % of the people pulling tigers and dropping the actual bombs. Will harm rather then rebuild that unity.