As governor of Texas, Mr Bush can hardly be judged on his foreign-policy achievements, but he has been a prominent supporter of immigration (not a bad guide in Republican terms) and he has inherited an experienced foreign-policy team from his father.
Last year, he joined a bipartisan group of business, law enforcement and religious leaders in signing the Indiana Compact, a set of principles to guide the state's immigration debate.
If American policymakers are looking for legal models on which to base new laws restricting immigration and expelling foreign lawbreakers, they have a handy guide: the Mexican constitution.