read this. i think it may help.
https://usacac.army.mil/sites/default/files/documents/cace/DCL/dcl_FirstPlaceEssay_0801.pdf
20 pages. quick read. especially read pp15-19
e.g.
>make it impracticable to enforce the laws
>by the ordinary course of judicial proceedings
>may call into Federal service such of the militia
>and use such of the armed forces
militia