Any criminal (IMHO), convicted of ID theft or fraud, fake age on their DL (for drinking), would have standing to sue the Govt. (state or fed) for unequal enforcement of the law.
Any Illegal that is here and been working is either: using fake docs (felonies), working under the table (tax fraud). There can be nothing else.
Those are felonies for you and I.
And there has to be already legal associations at work on the unequal enforcement. That'd be the 14th Amendment I believe. The lefties cling to that Amendment and the commerce clause.
I'll try to find something on the 'Net over the weekend.