What if Haitians were allowed to leave the disaster?

Tim Lee provides some interesting insight into how borders obstruct migration even during the worst humanitarian tragedies such as the earthquake in Haiti:

Obviously, no similar amenities were available to native Haitians. Many slept on the streets, and there remains a very real danger of mass starvation if aid doesn’t arrive in time. And of course most Haitians don’t have the option of hopping on a jet bound for the United States. That’s a tragedy because evacuation is crucial to crisis management. Hundreds of thousands of people fled New Orleans in the wake of Hurricane Katrina. Evacuation was not only a good decision for many of the people who evacuated; it also eased the load on overwhelmed emergency workers.

The difference, of course, is that American immigration law prevents the vast majority of Haitians from coming to the United States. True, the American government has grudgingly allowed Haitians who are already here illegally to stay for another 18 months. But the our immigration policy remains essentially hostile to Haitian immigrants:

[Homeland Security Secretary Janet] Napolitano warned that no new arrivals would get amnesty and the U.S. Coast Guard and other authorities would move quickly to stop new migrants. “People should not leave Haiti with the false belief that they will be entitled to TPS in the United States,” she said. She also said, “We are seeing no signs of any sort of migration of that nature at this point.”

In the wake of Katrina, Gov. Perry put out the welcome mat for Katrina refugees and even airlifted some refugees to other states whose emergency facilities weren’t so overtaxed. If he had instead tried to block people from fleeing to Texas from New Orleans in the days after Katrina, (something that, fortunately, he didn’t have the authority to do) we would all have castigated him for his callousness. Whatever minor inconveniences Texans might have suffered from the presence of New Orleanians would clearly be outweighed by the scale of the human tragedy that was Hurricane Katrina.

For reasons that aren’t clear to me, most Americans have very different intuitions about human beings in Haiti who are, if anything, in even more desperate straits. Not only are we not putting out the welcome mat, we’re actually spending taxpayer dollars to prevent Haitians from reaching our shores.