As it happens, the ruination of the United States is the result of the "contributions" of two groups of immigrants, Irish and Jewish.
For those who talk about how immigrants assimilate within a generation or two, it would be wise to note the generational status of the three men chiefly responsible for that ruination, Philip Hart, Emanuel Celler, and Edward Kennedy.
Philip Hart - Third-generation Irish immigrant
Emanuel Celler - Third-generation Jewish immigrant
Edward Kennedy - Fourth-generation Irish immigrant
It is clear that even to the fourth generation, immigrants are prone to maintaining their primary loyalty to their ethnic group, if not their nation of origin, rather than to the nation to which they have nominally grafted themselves. They are guided by the principle of "what is good for the Irish" or "what is good for the Jews" rather than "what is good for the Americans" or even "what is good for the USA".
No immigrant, or child, grandchild, or great-grandchild of immigrants, should have been permitted to vote or hold any office. Had the USA instituted such a policy, it might still be America instead of a multi-ethnic, white-minority idiocracy on the verge of crumbling into violent conflict and ethnic partition, as the ignorant public entertains itself by pretending to believe that Hamilton was either black or Hispanic.