I think you are correct. In which case, deporting them is no longer a valid threat. Prosecuting him for an illegal adoption might be possible - don’t know if there is a statute of limitations. It would certainly have suffice to explain some of his decisions (like Obama is qualified, etc) from 2000 to 2018 or so. They must have something on him - it is their style.
An illegal international adoption might have been enough to force his resignation. But the whole issue was hushed, even by the leftist NYT, who spike their investigation into Roberts’ adoption of Irish kids via Latin America.