The H-1B Visa program, begun in 1990, is designed to fill jobs requiring advanced science or computer skills — but only when American workers can't be found. Immigrants who are qualified receive temporary work permits, and federal guidelines say the practice should not "adversely affect the wages or working conditions" of American employees. Now they're a nightmare made real. Veteran employees are not only laid off, but required to train younger, cheaper replacements from other countries. It's happened at an iconic American company: Disney. Now tech giants Google, Microsoft and Facebook want more foreign workers. We hear how the H-1B program is dividing both parties in Congress and candidates on the trail to the White House.