While it’s true a significant portion of Americans support government restriction of immigration (around 30% want less immigration and another 40% want levels kept the same), this really isn’t indicative of what those people’s decisions in the marketplace would be. What sets the “immigration policy” in a free market, is the private decisions of many different people who choose who to (and who not to) hire, purchase from, lease to, sell to, etc. If a large sector of the domestic population prefers not to do business with foreigners, then immigration will be dramatically curtailed as they will find it extremely difficult to operate economically.
Discrimination by country of origin, however, entails costs which must be borne by the discriminator. An employer, for instance, necessarily the limits the pool of labor she can hire, therefore granting a competitive edge to the competition. And a customer reduces the businesses he can frequent, which can force him to pay more somewhere else. Etc, etc.
Government restrictions, in effect, transfer the costs of refusing to do business and otherwise associating with foreigners from private actors to the government. Where otherwise individuals would need to pay for the luxury of disassociation, a government policy of restricting immigration takes the voiced opinion of some and disperses the cost throughout the populace.
A Comparable Example
The same general concept played out in the post-reconstruction south. Some people said they wanted segregation and discrimination against blacks, but as I’ve pointed in another article, the people who would actually pay the cost of discrimination, like streetcar and train owners, preferred maximum profits instead. It didn’t matter that even vast majorities of the population had a bias against blacks because private discrimination includes a direct cost to the person making the decision. Segregation of these companies was only achieved after local and state governments forced it upon them.
In both cases, an arbitrary bias against a group of people, whether it be race or country of birth, entails costs that most private actors are not willing to pay. It’s only when governments take over the costs, that those private individuals can afford to act on their bias en masse. There may be a large number of people who say they want government restriction on immigration, but if these individuals were faced with the opportunity cost of completely disassociating with foreigners themselves, the result would likely be much different.
You can read more from Andrew Kern on Think Liberty here.