Why would the Federal government (DOJ) not challenge the laws constitutionality? They do that in the upper 48 all the time.
I have never seen the DOJ challenge a law’s constitutionality. Could you give an example?
Of course, private parties do so quite commonly.
Isnt the Federal govt claiming jurisdiction over immigration doing just that? I may be out on a limb here and I am not a lawyer, but if they can fight a state over this, why cant they fight a state over other bad law and policy?