Kaus: The negative outcome is we have 12 million illegals that we’re now trying to figure out what to do with, and it’s a real problem.

reason: Why is it a problem?

Kaus: Here’s the way I like to look at it. Why not have open borders? Nice! It’s sort of a libertarian idea.

reason: Yeah, very much.

Kaus: People want to come here. They want to work. They’re not a threat to national security. They don’t carry diseases.

reason: You’re describing a horrifying vision of the future.

Kaus: There are three reasons that’s bad. First, half the world would move here. It would drive down wages for unskilled Americans. I wrote a book called The End of Equality about how to be a liberal when incomes are growing more unequal and there’s nothing you can do about it. The reason there’s nothing you can do about it is because in the global economy people without skills in industrialized countries do very badly because that work is done in India or Bangladesh or somewhere else, so their only hope is that there’ll be enough jobs that have to be done in America that wages will stay at a decent level. If even those jobs are done by the rest of the world pouring into America, those people especially—people who are rising out of poverty, for example, people we wanted to leave the welfare rolls and go to work—you won’t be able to be an unskilled American and make a decent wage.

The two other things: There would be vast inequality. My whole book was designed to say we shouldn’t worry about inequality, and then Bob Shrum, the Democratic consultant, said, “Have you ever been to Latin America?” Latin America, if you’re middle class or rich, you live in an apartment building and there’s a guy with a machine gun on every floor. I don’t want to live in that kind of society. We would immediately have the inequality of Rio de Janeiro in Los Angeles.