The anti-immigrant game

In this op/ed, Professors Pratheepan Gulasekaram (Santa Clara) and Karthick Ramakrishnan (UC Riverside) explain the spate of state immigration enforcement laws as the result of partisan (Red State/Blue State) politics.  One question:  would the politics have kicked in if the states had not seen an uptick in migration from Mexico?  Put differently, why hasn't Alaska passed an immigration enforcement law while Georgia, Alabama, etc. have?

KJ