The interesting point is that the polarization is not so much among the public, although there's some of that. The polarization on the immigration issue is really between the elites and the public. In other words, this is not so much a right-left issue, which it is partly.

But the other audience, I think, is people in Central America because since last summer, they've been running ads down there - the United States government has - don't come, it's dangerous. You will be immediately deported. That's literally what it says in Spanish.

But it's more an up-versus-down issue because the research has shown that opinion leaders, whether they're elected officials, journalists, business leaders - it's academics, religious leaders - they have dramatically different views on immigration. A

Well, nobody's being deported - nobody - practically. And so what the people down there getting is the American government is telling us that you're not going to be able to stay. But, in fact, they're letting almost everybody stay. And so what they're trying to do is show that at least some people are going to get deported.

And they are much more skeptical of the very idea of having immigration limits, whereas the public - again, independents and Democrats, as well as Republicans, although not necessarily all in the same proportions - have a much stronger sense of the American government and American law having responsibility to Americans specifically rather than to people around the world. So the polarization is up versus down, not really right versus left.

Well, enforcement theater is OK if it's reality theater. In other words, obviously, you want to make it clear, you want to make people see that the law is being enforced.

The effects of illegal immigration aren't that different from those of legal immigration —an illiterate Central American farmer with a green card is just as unsuited for a 21st-century economy as an illiterate Central American farmer without a green card.