As Jonah’s article and Peter’s post demonstrate, many conservatives seem to feel that the presence in America of millions of illegal immigrants, and the extreme unlikelihood (or perhaps undesirability) of their all being deported, is a powerful argument for the Bush amnesty.

Let me start by conceding that under almost any policy regime there will be some illegal immigration. I do not believe in an immigration policy that matches “every willing worker” with “every willing employer”–a policy that would, theoretically, be compatible with an inflow of 20 million people a year. (As would Jonathan Adler’s policy of letting in every person who wants to work here, but nobody who wants to kill us–even assuming such a policy could be implemented.) But any policy that seeks to block a voluntary transaction is going to create a black market.

But the numbers matter. As it stands, every year 400,000 illegal immigrants are deported, leave the country voluntarily, or get green cards and become legal. Every year another 800,000 illegals enter the country. So we have a net increase of 400,000 to the illegal population. Are we really convinced that it is impossible to increase the 400,000 departures or reduce the 800,000 entries?

We are told that we have tried control of the borders, and it has failed. What we have not seriously tried is enforcement of the immigration laws in the interior. What if we stepped up deportation? The alternative here is not “deport 8 million people.” It’s deport a bunch more. Make other illegal immigrants who are here less eager to stay, and Mexicans considering it less eager to come. Let’s try some sort of worksite enforcement, which we never really have–even something as simple as allowing the IRS and the Social Security Administration share information about known illegals more widely. If you reduce the inflow and increase the outflow, you will stabilize the situation. You will still, to be sure, have plenty of illegals still here. Maybe then will be the time to talk about an amnesty.

Finally, Jonah: The existence of an “unholy mess” does not preclude the possibility that the mess can be made worse. Conservatives of all people should know that.