You have to wonder what else in the Senate's illegal alien amnesty scheme isn't practical as well:

The director of U.S. Citizenship and Immigration Services, the agency that would administer a new guest-worker program and rule on applications from millions of illegal aliens, says the pending Senate bill doesn't give his agency enough time to prepare for that giant task.

"Quite frankly, I don't think that's really practical. Ninety days to register 12 million people. Do the math," Emilio T. Gonzalez, who took over as director early this year, told The Washington Times...

...He acknowledged that fraud could be a huge problem under a plan that divides the illegal population by year, and said "it's a big 'depends'" as to whether there are documents that are secure enough to prove beyond a doubt that someone has earned the status...

He also offers a lukewarm defense against the charges by a whistleblower of widespread fraud at the USCIS.