Back when our immigration laws were last revised, in 1986, both left and right hated the idea of national identity cards. But now we have such cards in all but name and don't seem to mind being tracked by our banks or by Google or Facebook.
For years, we were told that effective enforcement was impossible. Now it's becoming technically very feasible.
And for years we were told that the tide of illegal immigrants would continue inexorably for years and decades to come. But now the illegal population is dropping because of reverse migration back to Mexico. And, in my view anyway, it's unlikely to increase to previous levels again.
Barack Obama continues to address the issue as if the facts had not changed. When he speaks to Hispanic groups, he calls for immigration legislation with mass legalization provisions, though he did nothing to advance it when his party had supermajorities.
And he's attracted attention by announcing his administration won't deport young illegals who meet certain conditions -- in line with the "Dream Act" bill he couldn't get Congress to pass.
In contrast, Mitt Romney in his speech to a Latino group limited his offer of citizenship to those who serve in the military. He was criticized for not setting out significant legalization provisions.
But Romney did address what is now the central problem with our immigration policy. And that is that current law is tilted against high-skill entrants who want to come here. We're shutting the door on math and science Ph.D.s even as Canada and Australia are welcoming them in.
The upholding of the Arizona law helps reduce the number of illegals, even as we debate which of them should be allowed to stay. But the key issue now is how we facilitate high-skill immigration.