Among the loyal hacks who permeate the Bush administration, Homeland Security Secretary Michael Chertoff has been one of the most reliably banal. So when Chertoff described the threat to the United States from so-called "clean skin" terrorists, most liberal bloggers understandably assumed this was just the latest example of that brand of casual conservative racism that brought us the "tar baby" slur from Tony Snow, Mitt Romney and John McCain. But, for once, Chertoff might deserve slightly more credit than that.
For the moment, I'll leave it to the armchair linguists to deconstruct the etymology of the expression "clean skin" to determine the extent of Chertoff's affront. His larger point, though, is that the United States will need to coordinate with the UK and EU to address the challenges posed by potential terrorists coming to the U.S. who like the 7/7 London bombers were citizens with valid documentation:

"We can do a good job with the known terrorists, if we have their name, or if we've previously arrested them and have their fingerprint on file...The fear has always been the so-called 'clean skin' - that's a person whose documents are completely legitimate, are not forged."

Whether that risk requires the extensive security checks and documentation the U.S. is proposing is a subject for debate. But Chertoff did make another assertion about the nature of the homegrown terrorism threat in the U.S. and Europe to which his xenophobic, anti-Muslim allies on the right should pay close attention:

"Our Muslim population is better educated and economically better off than the average American. So, from a standpoint of mobility in society, it's a successful immigrant population. To some degree, the whole country is a country of immigrants, and therefore there's no sense that we have insiders or outsiders. In some countries [in Europe], you had an influx of people that came in as a colonial legacy and may have always have felt, to some extent, that they were viewed as second-class citizens, and they've tended to impact and be kind of clustered in some areas."

On this latter point, I find myself in the unusual and uncomfortable position of agreeing with Michael Chertoff. In a piece from last August, "Homegrown Terrorism in the U.S. and Europe," I sought to explain the threat of radical Islamic extremism in Europe and its relative absence in the United States:

"Commentators of all political stripes, however, are too quick to draw conclusions about the comparative dangers of radical Islam within European and American Muslim communities. Predictably, conservatives use terror plots in England, clashes in France, train bombings in Spain and cartoon outrage in Denmark to attack the economic stagnation and social rigidity of Europe, while lauding the opportunity and equality of American society. In turn, liberals see multi-culturalism, affirmative action and group politics as a safety valve that provides American minorities political expression, electoral muscle and social standing missing in Europe.
The reality is much more complicated than that, defying such facile comparisons and ready morality plays. Simply put, Muslim immigrants have come to Europe and the United States for very different reasons. Whereas the small but diverse American Muslim community came to the U.S. primarily to pursue economic opportunity and escape political oppression, across the Continent the legacy of European colonialism has helped produce large, monolithic and increasingly restive Islamic populations with a multi-generational sense of grievance. Those different motivations and distinct histories, and not the supposed goodness or badness of America or Europe, explain today's gulf in domestic terror threats on either side of the Atlantic."

(For the full analysis, see "Homegrown Terrorism in the U.S. and Europe.")
As for Chertoff, his disastrous handling of Hurricane Katrina and his ham-fisted denials of his missteps have ensured that Americans will remain highly suspicious of him. Whether he deserves the opprobrium he is receiving for his Bidenesque comment about "clean skin" is another matter. But on the relative threat of homegrown terrorism in the United States, Michael Chertoff for once may actually have it right.