The Republican debate shows where comprehensive immigration reform is headed: Nowhere

But the effective reality, as National Review’s Ramesh Ponnuru has argued, is that immigration has become a Republican litmus-test issue. Rubio’s and Cruz’s deft maneuvering off their previous positions proves that. And Rubio is persuasive in arguing that a bill with legalization can’t be passed until the American people — i.e., Republican voters — are convinced that enforcement has been made effective.

My sense is that a President Rubio or President Cruz would be as bound by his current position as a President Trump. The demand for legalization has diminished — polls show Hispanics not much concerned — and Democrats will balk at legalization and insist on citizenship (for what they believe will be many new Democratic voters).

Paul Ryan is not likely to spend the huge amount of political capital required to pass a bill supported mainly by Democrats and opposed by a large majority of House Republicans.

Donald Trump’s candidacy, however it turns out, has changed the immigration calculus for Republican politicians. Some Republicans fear that Hispanics would make Arizona, Texas, and Florida as solidly Democratic as California, but these fears are unfounded.