[niftich]

Not to be pedantic, but the entire mechanism of coups d'état is that you step outside the legal framework and instead use intimidation and force.

If you fail, it's very, very often fatal. If you succeed, you retrofit some sketchy legal justification, or ignore the matter altogether.

[stonogo]

Part of running a coup in a democratic country is that your ground troops have to be on your side. This is much more difficult when every single soldier is made completely aware during indoctrination that domestic military action is almost completely illegal. Adding in the fact that there is no conscription in America, the likelihood of a military coup today is vanishingly small.