Prez:Therefore, comprehensive immigration reform must include a better system for verifying documents and work eligibility. A key part of that system should be a new identification card for every legal foreign worker. This card should use biometric technology, such as digital fingerprints, to make it tamper-proof. A tamper-proof card would help us enforce the law, and leave employers with no excuse for violating it. And by making it harder for illegal immigrants to find work in our country, we would discourage people from crossing the border illegally in the first place.