Despite its pro-labor bent, the Obama NLRB has reluctantly followed Supreme Court precedent and ruled that undocumented workers whose rights were violated under federal labor law cannot obtain back pay even though their illegal immigrant status was known by the employer when they were hired. Despite the Supreme Court's decision in Hoffman Plastic Compounds Inc. v. NLRB, an ALJ had ruled against the company because it was the employer, not the workers, who violated immigration laws by failing to verify the workers' authorization status.

A three-member panel of the Board, however, unanimously agreed that Hoffman Plastic is controlling even though the workers never presented fraudulent documents to obtain their jobs and the employer knew they were undocumented. However, in a concurring opinion, Liebman and Pearce said, "We . . . remain convinced that the result in this case – an order relieving the employer of economic responsibility for its unlawful conduct – can only serve to frustrate the policies of both the [NLRA] and our nation's immigration laws." Liebman and Pearce also made it clear that this issue has not been finally resolved. They wrote, "We would be willing to consider in a future case any remedy within our statutory powers that would prevent an employer that discriminates against undocumented workers because of their protected activity from being unjustly enriched by its unlawful conduct."