Like John, I "got people" too. Here is a summary of points made in response to the question by my Competitive Enteprise Institute colleague, policy analyst Alex Nowrasteh.
The immigration policy debate mostly concerns issues of economic protectionism and issues concerning the rule of law. On the first issue, the body politic has an anti-foreign bias. This doesn’t mean that people hate foreigners, it’s just that many see the economy as a zero-sum gain so trade, and immigration is immediately suspect in their minds.
In the minds of most Americans, immigration automatically means lower wages and more competition for scarce jobs. But even most serious studies doubtful of the positive effects of immigration,, such as those by George Borjas, envision only a slight decrease in wages for lower skilled workers with increases for many other groups. It’s universally accepted that immigration increases income inequality, but also increases the size of the total pie with long run effects on wages approaching zero or slightly positive.
While Borjas has pointed out issues raised by immigration, the solution is not more restrictive policies but legalization of future flows of immigrants. David Card is right as to the economic effects of immigration. More importantly, the magnitude of immigration policy’s impact on the world economy is generally understated. According to Hamilton and Whalley’s seminal 1984 paper "Efficiency and Distributional Implications of Global Restrictions On Labor Mobility," global economic gains from a more permissive immigration strategy would be massive.
As to the law and order issue, immigration restrictionists want to enforce the law, deport millions of undocumented immigrants, and, oddly, prevent future flows of legal immigrants. No doubt this is a charade for some members of that group but most generally believe it. They believe that the rule of law has been vital to the economics success of our country and is worthy of being upheld.
But the point that needs to be made is that the rule of law depends on the existence of good law. We don’t live in a totalitarian regime, so people break laws on a massive scale that are impossible to enforce. There are approximately 10.8 million undocumented immigrants with 94% of them illegally being employed by millions of employers. Millions of Americans knowingly benefit for this exchange.
In a free society, when laws are ignored it is a threat to the institution of the rule of law. But solving that problem does not and should not require greater enforcement. It requires a change in the law so that people can conform with economic reality.
Much as prohibition of liquor created crime and pervasive black markets, immigration restrictions do the same. When legislation and reality are in conflict, reality always wins. The goal is to adapt the legislation so that the rule of law isn’t a casualty.