Where's the due process of law in this?
Nowhere, obviously. The law is unconstitutional on its face. NRA is wrong to go along with this tyranny.
there is no due process in this
these orders are valid whether or not they are served
I agree, but this legislation is somewhat redundant. The same thing has existed as federal law since 1997 in the form of the "Domestic Violence Offender Gun Ban" or "Lautenberg Amendment" (to the Omnibus Appropriations bill of that year).