Reagan enforced the laws on the books. Bush didn’t.
Not only that, Reagan signed legislation making what he did at least legal.
Bush failed to abide by the U. S. Constitution, Article 4 Section 4 by failing to protect the states from invasion. He did not enforce the laws on the books, specifically the legislation Reagan signed.
As I understand it, Obama will by executive order declare certain groups to be free from being deportable. That isn’t just failing to enforce laws. It is a change to law by Presidential edict.
'Reagan's Immigration and Naturalization Service commissioner announced that minor children of parents granted amnesty by the law would get protection from deportation. '
Did not enforce the law.
Bush I:
'acting through the Immigration and Naturalization Service, established a "family fairness" in which family members living with a legalizing immigrant and who were in the U.S. before passage of the 1986 law were granted protection from deportation and authorized to seek employment. The administration estimated up to 1.5 million people would be covered by the policy.'
Did not enforce the law.