Sometimes immigration critics will make a watered-down version of the prudential argument. Instead of claiming that an increase in immigration will destroy the country outright, they object that immigrants inflict unnecessarily painful costs on their host nation. These costs can be roughly divided into two categories – welfare costs and crime costs.
If our nation cannot afford to give immigrants access to welfare, then the solution is simple. We should stop giving immigrants access to welfare. It does immigrants no favor to deny them both welfare and their right to immigrate.
The evidence that immigrants commit more crimes seems shaky to me. But even if it were true, it would not follow that America should restrict immigration. Immigrant groups historically cluster together in the same neighborhoods. Immigrants will bear the brunt of their own supposed costs in crime. Although we may weep for them, if we shut our eyes to the suffering they would have experienced in their native country, we are only shedding crocodile tears. It is best to let them make their own choice between living in a high-crime neighborhood in the US and a possibly higher-crime one in their home country.
I haven’t put too much effort into rebutting the externality argument for two reasons. First, many of the stronger “externality” arguments are variations on the “prudential” arguments discussed before. Second, I find it difficult to care. The mere suspicion of externalities is not a justification for denying central human rights. We could not legitimately throw poor Americans in prison just because we hoped this would reduce crime or the burden on the welfare state. Nor could we deport them to Mexico. Nor should we be able to deport poor Mexican immigrants.