Douthat's Populist Nationalism

Grinding his Christian universalism under his nationalist heel, Ross Douthat breezily sets forth a multiply fallacious argument on the premise that there is no intellectual or moral difference between confiscatory redistribution and voluntary exchange when citizens of other countries are involved:

A slightly better way of putting what Matt is driving at, I think, is this: Large-scale immigration from Mexico to the United States is a form of de facto humanitarianism, and since Americans are generally leery of humanitarian spending (primarily because we overestimate the size of our existing foreign aid budget), liberal humanitarians have a vested interest in preserving the existing immigration system. It’s a rare issue where business interests line up on the side of raising the living standards of Third World peasants, and why mess with a good thing? Better, as Matt suggests, to go after the global elite in other arenas – like tax policy, say – where the business class’s preferred policies don’t have humanitarian externalities.
To which one might respond that there’s something slightly perverse about pursuing humanitarian ends through policies that lower the incomes of your poorest citizens and raise the incomes of your richest citizens. If I proposed a new AIDS-in-Africa initiative and advocated funding it through a regressive tax that included a tax credit for families making over $75,000, I doubt that many liberals would line up behind the proposal.

I'll muster some charity and assume that Ross is simply confused here. But he really is badly confused.
It's a rather profound error to characterize voluntary trade between American employers and Mexicans workers as equivalent to “humanitarian spending,” as if money tax revenue had been withdrawn from the Treasury and sent to Mexicans. There is indeed a pecuniary externality of Mexican workers in the American labor market — downward price pressure from competition — and this can indeed have an effect on the pattern of American incomes. But it is a pretty basic and embarrassing mistake to confuse (1) coercive state confiscation and reallocation of income with (2) changing patterns of income from voluntary exchange.
Perhaps Ross really does think that the U.S. government has taken money from the pockets of the producers of Oceans 13 by refusing to ban Pirates of the Carribean, but I think he's smarter than that. Government tax policy requires justification. Distribution of tax revenue require justification. Exercising our rights doesn't.
That Ross is liable see the issue in this weird, mistaken way does indicate that he thinks some sort of nationalism is the legitimate moral baseline. The liberal (in the broad sense) presumption of freedom, on the other hand, has it that unrestricted voluntary cooperation between human beings is the moral baseline. Deviations from this require special justification. Given the liberal baseline, labor market restrictions (that's what we're talking about here — whether to further restrict American labor markets), besides standing as a violation of the rights of both Americans and Mexicans to freely associate and trade with one another, amount to a transfer of income from Mexican workers and American consumers to some low-skilled American workers. In addition to the basic violation of liberty, this is a monstrously regressive transfer, harming Mexican workers much more than it helps low-skilled American workers.
But Ross seems to understand the situation in a way that, as far as I can tell, completely discounts the welfare gain to Mexicans, and conceives of the effects of millions of people exercising their human rights as requiring some kind of special justification. This makes sense only relative to a nationalist worldview where “humanitarian spending” is something benighted “liberal humanitarians” want to do and the actual welfare effects of this “spending” on foreigners is simply irrelevant to the moral calculus; all that matters is the effect of the policy on persons with valid U.S. passports. If the policy turns out to (on average) reduce the incomes of low-skilled U.S. workers and raise the incomes of  higher-skilled U.S. workers, then it's evidently “perverse.” So if we have to placate uppity U.S. humanitarian liberals by throwing money at poor people somewhere, surely this isn't the way we want to do it.
But what about Mexican workers and their families? Who cares! Wrong passport! What about the lost liberty of Americans to trade with Mexican workers on the labor market? Well, I guess we decide what liberties Americans have based on some undermotivated nation-level idea of just distribution. Why? Who knows!? (And who cares if it keeps Mexicans out?!) I don't think Ross denies the fact that Mexican immigration on average makes Americans better off. So a merely utilitarian nationalism would have us accept even more immigrants. You could try to dress Ross's view up as Rawlsian nationalism, demanding that a policy improve the lot of the least well-off Americans. But I think Ross's argument really amounts to populist nationalism, appealing to populist class sentiments to help achieve a goal he wants anyway: a less Mexican America.  
Well, I understand that a certain kind of nationalism may well be the default baseline for a broad swathe of American public opinion, but that makes it no less repugnant from the perspective of both human liberty and human welfare. Democrats and then Republicans in the American South long succeeded in winning elections by drumming up racist majorities. (Integrating blacks fully into the labor market no doubt put downward pressure on low-skilled white wages, and I don't doubt successful politicians brought this up.) But I don't think this speaks well of our democracy.
This whole issue really turns on what we take to be the relevant moral baseline. I would very much like to see Ross defend what I see as his form of nationalism. From where I sit, there's something more than “slightly perverse” about denying our human rights to freely cooperate and locking very poor people out of our labor markets so that relatively wealthy people whose grandparents got here first don't have to take a paycut.