But many undocumented workers avoid joining unions "because they are under constant threat of deportation, " said Ana Avendano, head of the AFL-CIO's immigration and community-action program.

WSJ: Unions Seize on Immigration Debate

Ana Avendano, head of the AFL-CIO's immigration and community action program, said the Harrisburg situation will prompt the federation to address the J-1 visa in negotiations for an immigration overhaul.

WSJ: Guest Worker Visa Troubles Visit McDonald's