Third World Momentum...

A textbook case...

The ability to make uniform rules of Naturalization does give Congress the power to control how many immigrants can be naturalized in a given year and under what conditions. Naturalization used to be solely carried out by the States themselves but Congress had to pretty much federalize the Naturalization process because of massive fraud and bought State judges as a result of the Irish waves. The Irish decided if they wanted to continue flooding New York unmolested by State laws they needed instant political power -- and to get political power they needed to come up with lots of citizen voters very quickly!

H/T federalist blog