Big Labor likes to suggest that its beef with guest workers is that they “steal” American jobs, an argument designed to appeal to populist fervors. This is hokum. Labor unions are hugely in favor of giving today’s 11 million illegal immigrants a path to citizenship, a move that would free up these shadow workers to “steal” far more American jobs than any guest-worker program.

The issue here is instead one of power—via organizing. The labor movement is hemorrhaging members and is now at a crisis stage. Unions see an opportunity to pull in immigrants but have been frustrated in their efforts by undocumented workers fearful of being caught and deported. This would change with a path to citizenship. And it explains why AFL-CIO chief Richard Trumka sat in the front row at President Obama’s speech and gave his full support to the “top priority” of immigration reform: “citizenship.”

A guest-worker program, by contrast, is of no use to Big Labor. Temporary workers are not open to union cards. Worse from the union perspective, these nonunionized immigrant workers can swell the ranks of certain industries, decreasing union power to force business to give in to their demands.