Democrats opposed the ratification of the Central America Free Trade Agreement last year for fear that it would undercut American workers made to compete with cheap Latin American labor. The problem the Democrats must have had with this effect on American workers was that it was too indirect. The party now favors importing lots of that same cheap Latin American labor directly into the United States.

Bizarrely, it is the Democrats who most strongly support a lax immigration system that acts as a subsidy to business interests eager to hire workers at the lowest wages possible and to upper-middle-class Americans who don’t want to pay too much to have someone mow their lawns. And this subsidy comes at the expense of American low-skill workers, many of them African-American and Hispanic, who are supposed to be the heart of the Democratic Party.

The thesis of the Thomas Frank book, “What’s the Matter with Kansas?” has become gospel for Democrats – that working-class voters in the heartland are misled into voting against their economic interests by supporting Republicans. That argument needs an overhaul now that it is clear that Democrats think there’s nothing the matter with Kansas, or anywhere else, that can’t be solved by more wage-competition from a flood of foreign low-skill workers.

“This is the one issue,” said Rosemary Jenks of the pro-enforcement group Numbers USA, “where Democrats sell out all their principles.” The party, and its allies in the unions, no doubt see potential new voters and members in the influx of Hispanic newcomers. They are also increasingly in the grip of a grievance-based ethnic politics that champions the rights of illegals, and of a post-national “we are the world” ideology that has little use for nationhood and borders.

There is disagreement about how much the wages of native low-skill workers are depressed by cheap immigrant labor, but it is common sense that as the supply of cheap labor increases, its price declines. Some notable liberal writers – unconcerned with cynical electoral calculations – still view immigration through this prism. Paul Krugman, Nicholas Kristof and Michael Lind have all noted on The New York Times op-ed page the economic senselessness of bringing more low-skill labor into the country. “The cold reality,” Kristof writes, “is that admitting poor immigrants often means hurting poor Americans.”

There was a time when liberals writing such things wouldn’t have stood out. The great labor leader Samuel Gompers supported a more restrictive immigration policy in the early 20th century to boost the wages of native workers. Liberal icon Cesar Chavez, the organizer of agricultural workers, excoriated illegal immigration. The end of the “bracero” guest-worker program in the mid-1960s led to a one-time increase in the wages of Chavez’s workers by 40 percent.

Democrats now figure that new immigrants can swell the ranks of their voters. Unions make the same kind of calculation, counting on signing up immigrants to make up for dwindling native membership. As Mark Krikorian of the Center for Immigration Studies said, “American workers turned their backs on unions, and now unions have turned their backs on them.” Even if the AFL-CIO leadership welcomes a massive dose of immigrant labor, its rank and file still knows the economic score. When Sen. John McCain, R-Ariz., defended his amnesty plan at a meeting of the AFL-CIO’s Building and Construction Trades Department, he was roundly booed.

This split between the Democratic elite and the working-class portion of its political base presents an opportunity for Republicans, assuming they can see past the parochial interests of their business supporters. Pro-enforcement House Republicans have done just that. Majority Whip Roy Blunt noted the opposition of the U.S. Chamber of Commerce to the GOP enforcement bill last year, and emphasized how comfortable he was being on the other side of the Chamber on an issue.

Once, that kind of attitude would have been endorsed by liberals – back before they were happy to let mass immigration trump the interests of American workers.

Rich Lowry is a syndicated columnist. He can be reached via e-mail at: [email protected]