Biometric ID Cards Thwart Illegal Employment?

Time magazine recently quoted two Senators claiming that a biometric ID card will help stop illegal employment because employers can check and determine if the person they seek to hire is eligible for work. Here’s the trust of the legislation:

“If you say they can’t get a job when they come here, you’ll stop it,” Schumer told the Wall Street Journal.

Unfortunately as long as cash is used to transact business, illegal immigrants will be able to find employment. The question is simply: what percentage?

[I should also note there are a host of security issues that surround the ID card and the biometric data stored on it. Card cloning is one issue.]