Robert Samuelson devotes this week's column to the immigration issue:

Immigration is crawling its way back onto the national agenda -- and not just as a footnote to keeping terrorists out. This year Congress enacted a law intended to prevent illegal immigrants from getting state driver's licenses; the volunteer "minutemen" who recently patrolled the porous Arizona border with Mexico attracted huge attention, and members of Congress from both parties are crafting proposals to deal with illegal immigration. All this is good. But unless we're brutally candid with ourselves, it won't amount to much. Being brutally candid means recognizing that the huge and largely uncontrolled flow of unskilled Latino workers into the United States is increasingly sabotaging the assimilation process.

He cites a new study by Harvard University economists George Borjas and Lawrence Katz showing that Mexican immigrants and their children are not quickly climbing the economic ladder.

And he makes this point: "For today's Mexican immigrants (legal or illegal), the closest competitors are tomorrow's Mexican immigrants (legal or illegal). The more who arrive, the harder it will be for low-skilled workers already here to advance."